Tüm alıştırma soruları

2195 soru

Soru 441Soru

If nn is a real number, is nn an integer?

(1) n23nn^2 - 3n is an integer.
(2) n2+5nn^2 + 5n is an integer.

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Cevap: BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

Cevap

Both statements together are sufficient to answer definitively that nn is an integer, but neither statement alone is sufficient.
Neither statement alone is sufficient because quadratic equations of the form n23n=kn^2 - 3n = k and n2+5n=mn^2 + 5n = m have non-integer real roots for certain integer values of kk and mm. When both statements are combined, subtracting the two equations reveals that 8n8n is equal to an integer pp, so n=p8n = \frac{p}{8}. Substituting n=p8n = \frac{p}{8} into n23nn^2 - 3n requires p(p24)64\frac{p(p-24)}{64} to be an integer. Examining the power of 2 in p(p24)p(p-24) proves that pp must be divisible by 8, which guarantees that nn is an integer. Thus, the two statements together provide a definitive 'Yes' answer.

Adım Adım Çözüm

1
Evaluate Statement (1) independently.
Statement (1) is NOT sufficient.
If n23n=1n^2 - 3n = -1 (an integer), then n23n+1=0n^2 - 3n + 1 = 0, giving n=3+52n = \frac{3 + \sqrt{5}}{2}, which is not an integer. However, if n=3n = 3, n23n=0n^2 - 3n = 0, which is an integer. Thus, nn can be an integer or a non-integer.
2
Evaluate Statement (2) independently.
Statement (2) is NOT sufficient.
If n2+5n=1n^2 + 5n = 1 (an integer), then n2+5n1=0n^2 + 5n - 1 = 0, giving n=5+292n = \frac{-5 + \sqrt{29}}{2}, which is not an integer. However, if n=1n = 1, n2+5n=6n^2 + 5n = 6, which is an integer. Thus, nn can be an integer or a non-integer.
3
Combine Statement (1) and Statement (2).
Deduce that 8n8n must be an integer.
Let n23n=kn^2 - 3n = k and n2+5n=mn^2 + 5n = m, where kk and mm are integers. Subtracting the first equation from the second yields (n2+5n)(n23n)=mk    8n=mk(n^2 + 5n) - (n^2 - 3n) = m - k \implies 8n = m - k. Since mkm - k is an integer, let 8n=p8n = p for some integer pp. Hence, n=p8n = \frac{p}{8}.
4
Analyze whether n=p8n = \frac{p}{8} can be a non-integer fraction.
nn MUST be an integer, making BOTH statements TOGETHER sufficient.
Substitute n=p8n = \frac{p}{8} back into Statement (1): n23n=p2643p8=p224p64n^2 - 3n = \frac{p^2}{64} - \frac{3p}{8} = \frac{p^2 - 24p}{64}. For this value to be an integer, p224p=p(p24)p^2 - 24p = p(p - 24) must be divisible by 64=2664 = 2^6. If pp is odd, p24p - 24 is odd, so p(p24)p(p-24) is odd and not divisible by 64. If pp is a multiple of 2 but not 4 (p=2bp = 2b with bb odd), p(p24)=4b(b12)p(p-24) = 4b(b-12), containing only 222^2 factors of 2. If pp is a multiple of 4 but not 8 (p=4bp = 4b with bb odd), p(p24)=16b(b6)p(p-24) = 16b(b-6), containing only 242^4 factors of 2. Thus, for p(p24)p(p-24) to contain 262^6, pp must be a multiple of 8. If pp is a multiple of 8, then n=p8n = \frac{p}{8} must be an integer.

Anahtar Kavram

Evaluating integer constraints vs. real numbers in Data Sufficiency through algebraic elimination and prime factorization of rational expressions.
Soru 442Soru

An urban transit authority conducted a comprehensive survey of all commuter rail passengers traveling on Line X during peak morning hours. The survey established that every passenger who traveled with a monthly pass completed their journey in under 45 minutes. The survey also determined that 30 percent of all morning peak passengers on Line X did not travel with a monthly pass, and that no passenger without a monthly pass completed their journey in under 30 minutes.

If the statements above are true, which of the following must also be true on the basis of them?

Cevabı ve açıklamayı göster

Cevap: At least some morning peak passengers on Line X took 30 minutes or more to complete their journey.

Cevap

The statement that at least some morning peak passengers on Line X took 30 minutes or more to complete their journey must be true.
The correct answer is strictly derived from combining two premises: 30 percent of peak morning passengers did not hold monthly passes, and zero passengers without monthly passes completed their journey in under 30 minutes. Therefore, all passengers within that 30-percent subset took at least 30 minutes (30 minutes or longer), guaranteeing that at least some passengers took 30 minutes or more.

Adım Adım Çözüm

1
Analyze the explicit premises given in the stimulus.
Premise 1: 100% of monthly pass holders finished in under 45 minutes. Premise 2: 30% of total passengers did not hold a monthly pass. Premise 3: 0% of non-pass holders finished in under 30 minutes.
Inference questions require strictly factual evaluation without external assumptions.
2
Synthesize the facts regarding non-pass holders.
Since non-pass holders make up 30% of the total passenger population and none of them completed their trip in under 30 minutes, every member of this 30% group took 30 minutes or longer.
If a subset of passengers exists and none of them took under 30 minutes, then every passenger in that subset took 30 minutes or more.
3
Evaluate the options to distinguish a strict deduction from unstated assumptions and speculative claims.
The option asserting that at least some passengers took 30 minutes or more is guaranteed by the 30% group of non-pass holders.
A valid GMAT inference must be 100% true based strictly on the premises.

Anahtar Kavram

Distinguishing strict logical deductions (Must Be True) from unstated causal assumptions or speculative extrapolations.
Tahmini Süre:2m 0s
Soru 443Soru

Conservators at a prominent museum have long maintained that installing centralized precision-humidity control systems in historic buildings is essential for preventing the degradation of centuries-old wooden panel paintings. However, a recent study of vintage panel deterioration shows no significant difference in structural decay between paintings housed in high-tech climate-controlled rooms and those kept in traditional buildings with simple passive ventilation. Because wooden panels naturally adjust to gradual seasonal fluctuations without suffering stress fractures, the costly replacement of traditional ventilation systems with complex environmental controls is an unnecessary expenditure for preserving these artworks.

Which of the following best describes the roles played by the two bolded statements in the argument?

Cevabı ve açıklamayı göster

Cevap: The first presents findings used to challenge a traditional position; the second is the main conclusion drawn by the argument.

Cevap

The correct option identifies the first statement as findings used to challenge a traditional position and the second statement as the main conclusion of the argument.
The correct answer accurately characterizes the flow of logic. The argument begins with a traditional opinion held by museum conservators. The first bolded portion delivers study results demonstrating that high-tech systems produce no better results than traditional passive ventilation, thereby directly challenging the conservators' view. The second bolded portion is the final judgment reached by the author—that expensive system replacement is an unnecessary expenditure.

Adım Adım Çözüm

1
Analyze the main argument structure and main conclusion
The argument opens by describing a long-held belief by conservators, introduces new study findings after 'However', provides an explanatory premise, and concludes that upgrading ventilation systems is unnecessary.
Identifying the author's core claim establishes the ultimate point of the passage.
2
Determine the structural role of the first bolded statement
The first bolded statement presents empirical study findings showing no difference in decay, which undermines the conservators' claim that high-tech systems are essential.
Transition words like 'However' signal that this finding challenges the previous view.
3
Determine the structural role of the second bolded statement
The second bolded statement states that replacing traditional systems is an unnecessary expenditure, which is the main conclusion justified by the study findings and natural adjustment mechanism.
This is the ultimate claim that the author is advocating in the passage.

Anahtar Kavram

Boldface Argument Structure Analysis
Soru 444Soru

Passage:
During the late nineteenth century, the North American timber industry experienced a rapid transition from river-driven log drives to specialized rail transport. Early river drives relied heavily on seasonal spring freshets—periods of high water caused by snowmelt—to flush timber downstream to coastal sawmills. Consequently, timber operations remained idle throughout the winter and late summer, leaving capital equipment underutilized for nearly seven months each year. In contrast, the implementation of narrow-gauge logging railways allowed timber syndicates to harvest and haul logs continuously regardless of weather conditions or river volume. Although railway construction demanded substantial initial capital outlay, the resulting year-round operations significantly lowered fixed costs per unit of lumber produced. Furthermore, year-round harvesting enabled sawmills to supply urban construction markets during winter months when timber prices historically peaked due to seasonal shortages, thereby capturing substantial market premiums that easily offset the debt service on railway infrastructure.

Statement: Based on the passage, timber syndicates that adopted narrow-gauge logging railways were able to offset their infrastructure debt service in part by selling lumber during months when market prices were elevated due to seasonal supply shortages.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

The statement is True. By combining information about year-round railway transport and winter market price peaks caused by shortages, it can be validly inferred that winter sales helped offset infrastructure debt.
The statement is correct because the passage directly connects the adoption of narrow-gauge railways to year-round harvesting, which allowed sawmills to take advantage of winter price peaks caused by seasonal shortages and capture premiums that offset railway debt service.

Adım Adım Çözüm

1
Identify the operational change brought by narrow-gauge railways.
The passage establishes that narrow-gauge railways enabled timber syndicates to harvest and haul timber year-round, including during winter when river drives were previously idle.
Establishing year-round operational capability is essential for evaluating winter sales activity.
2
Analyze the financial consequences of winter market sales.
The passage states that winter timber prices peaked due to seasonal shortages and that selling during this time captured premiums that offset debt service on railway infrastructure.
Connecting market conditions to financial outcomes shows how infrastructure debt was offset.
3
Synthesize the findings to evaluate the statement.
Combining operational continuous harvesting with winter price premiums confirms that selling during high-price shortage periods offset railway debt.
Multi-sentence synthesis validates the truth of the given statement.

Anahtar Kavram

Multi-Sentence Synthesis Inferences
Soru 445Soru

Executive board members at a major technology firm maintain that purchasing comprehensive cybersecurity insurance is an unnecessary expense, contending that internal cash reserves are sufficient to absorb potential breach penalties. However, recent empirical studies demonstrate that the indirect financial damage of a major breach—including reputational harm and lost customer lifetime value—routinely exceeds a firm’s total liquid reserves by several orders of magnitude. Furthermore, insurance underwriters require continuous security audits that proactively identify software vulnerabilities before exploit incidents occur. Therefore, relying exclusively on internal financial reserves to manage enterprise cyber risk is an unsound management strategy.

In the argument given, the two boldfaced portions play which of the following roles?

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Cevap: The first is evidence presented to undermine the position held by the board members; the second is the author's main conclusion.

Cevap

The first boldfaced statement provides factual evidence used to counter the board members' plan, while the second boldfaced statement serves as the author's main conclusion.
The correct answer accurately identifies the logical flow of the argument: the author uses empirical data regarding indirect breach costs (first bolded statement) to directly weaken the board members' claim, culminating in the final verdict that relying solely on reserves is unsound (second bolded statement, the main conclusion).

Adım Adım Çözüm

1
Analyze the structural position of the first bolded statement.
The text preceding the first bolded statement presents the board's belief (reserves are sufficient). The pivot word 'However' introduces empirical evidence showing reserves are actually far smaller than breach costs.
This shows the first bolded statement functions as premise evidence opposing the board's stance.
2
Analyze the structural position of the second bolded statement.
The word 'Therefore' introduces the second bolded statement, taking the evidence provided and forming the final evaluation that relying on cash reserves is unsound.
This confirms the second bolded statement is the main conclusion of the passage.
3
Match structural roles to the options.
The option stating that the first is evidence undermining the board's position and the second is the main conclusion accurately describes both roles.
It correctly identifies premise evidence vs. main conclusion without misattributing author viewpoint.

Anahtar Kavram

Analyzing Bolded Statement Roles (Premise vs. Main Conclusion & Opposing Stance)
Soru 446Soru

To curb local air pollution, urban planners have advocated that the city municipal authority mandate all commercial delivery fleets to adopt zero-emission vehicles by the end of the decade. Industry representatives oppose the plan, claiming that the substantial capital expenditure required will bankrupt smaller logistics firms and disrupt urban supply chains. However, this objection relies on an incomplete picture of the policy package. The municipal authority has pledged to finance the installation of free fleet-charging hubs and provide low-interest loans specifically tailored for small operators. Consequently, the implementation of the mandate will not trigger the widespread failure of small logistics businesses.

In the argument given, the two boldfaced portions play which of the following roles?

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Cevap: The first is a proposed policy that the argument defends against a specific objection; the second is evidence offered to demonstrate that the objection is unwarranted.

Cevap

The first bolded portion is a proposed policy that the argument defends against an objection, while the second bolded portion is evidence cited to show that the objection is unfounded.
The correct answer accurately characterizes both bolded statements. The first bolded statement presents the proposed mandate that forms the central subject of discussion; the author defends this mandate against an industry objection. The second bolded statement introduces explicit evidence regarding municipal funding and loans, demonstrating why the industry's financial objection is unfounded.

Adım Adım Çözüm

1
Analyze the main conclusion and overall structure of the argument.
The author concludes that the proposed mandate will not cause small logistics businesses to fail, contradicting the objection raised by industry representatives.
Identifying the author's ultimate conclusion provides the framework for assessing the function of each sentence.
2
Determine the role of the first bolded statement.
The first bolded statement describes the proposed mandate to adopt zero-emission vehicles, which industry representatives oppose but the author defends.
Understanding whether the author agrees with or opposes the first statement clarifies its functional role.
3
Determine the role of the second bolded statement.
The second bolded statement presents factual evidence (financing charging hubs and providing low-interest loans) that directly undermines the opponents' claim of financial hardship.
Evaluating how the second statement interacts with the opponents' claim shows that it acts as counter-evidence supporting the author's main conclusion.

Anahtar Kavram

Analyzing Bolded Statement Roles in Critical Reasoning
Soru 447Soru

For over a century, economic historians viewed medieval merchant guilds primarily as rent-seeking cartels designed to restrict competition, artificially inflate prices, and secure legal monopolies from local sovereigns. This traditional consensus, heavily influenced by classical economic theory, posited that guilds generated deadweight losses that stifled urban commercial expansion until Enlightenment-era market liberalization dismantled their institutional grip. However, in the late twentieth century, revisionist scholars challenged this view, arguing that guilds emerged primarily to solve severe information asymmetries and enforcement problems inherent to long-distance trade. According to this institution-focused framework, guilds provided crucial public goods—such as contract enforcement across political jurisdictions, quality verification for traded merchandise, and collective diplomatic bargaining leverage against predatory rulers who might otherwise confiscate foreign merchants' property.

Recently, a third wave of scholarship has sought to synthesize these opposing perspectives by examining the temporal evolution of guild functionality. These micro-historical analyses suggest that whether a guild acted predominantly as an efficiency-enhancing institution or a growth-inhibiting cartel depended largely on the maturity of surrounding state apparatuses. In the early medieval period, when centralized legal structures were rudimentary or non-existent, merchant guilds operated essentially as privatized governance systems that significantly reduced transaction costs and expanded trade volumes. However, as territorial states developed robust judicial systems and public enforcement mechanisms during the early modern era, the governance functions of guilds became redundant. Rather than dissolving voluntarily, mature guilds leveraged their accumulated wealth and institutional influence to lobby state authorities for statutory monopolies, effectively transitioning from growth-promoting institutions into rent-seeking cartels. Thus, the debate is not whether guilds were inherently efficient or predatory, but how shifting external institutional contexts transformed their economic impact over time.

Which of the following best describes the overall rhetorical plan of the passage?

Cevabı ve açıklamayı göster

Cevap: It introduces a long-standing historical interpretation, outlines a revisionist counter-hypothesis, and then presents a nuanced synthesis that reconciles the two by introducing a contextual variable.

Cevap

The correct option is the one stating that the passage introduces a long-standing historical interpretation, outlines a revisionist counter-hypothesis, and then presents a nuanced synthesis that reconciles the two by introducing a contextual variable.
The passage follows a classic three-part historiographical structure. Paragraph 1 introduces the traditional 100-year consensus (cartel view) and contrasts it with late 20th-century revisionism (efficiency view). Paragraph 2 introduces a third wave of scholarship that reconciles both views by showing that guilds evolved from efficiency-enhancing to rent-seeking depending on the maturity of state apparatuses (the contextual variable). The option stating that the passage introduces an established interpretation, outlines a revisionist counter-hypothesis, and presents a synthesis reconciling the two correctly reflects this complete rhetorical blueprint.

Adım Adım Çözüm

1
Analyze the structural role of the first paragraph
The first paragraph establishes the traditional view (guilds as rent-seeking cartels) and introduces a revisionist counter-hypothesis (guilds as efficiency-enhancing providers of public goods).
Understanding paragraph division helps identify major structural shifts.
2
Analyze the structural role of the second paragraph
The second paragraph presents a 'third wave of scholarship' that synthesizes both views using state maturity (external institutional context) as the key variable explaining why guilds shifted from efficient to rent-seeking over time.
Tracking transition phrases ('Recently, a third wave...', 'Thus...') reveals the author's rhetorical resolution.
3
Evaluate option choices against the identified passage structure
The option identifying a long-standing view, a revisionist challenge, and a reconciling synthesis correctly maps to the full arc of the passage.
The correct rhetorical description must reflect the relationship between all presented viewpoints.

Anahtar Kavram

Rhetorical Organization of Multi-Viewpoint Passages
Tahmini Süre:2m 15s
Soru 448Soru

For all non-zero real numbers xx and yy such that xyx \neq y, the Data Sufficiency Yes/No target question "Is xy+yx>2\frac{x}{y} + \frac{y}{x} > 2?" is algebraically equivalent to the simplified target question "Is xy>0xy > 0?"

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
The statement is True because rewriting the inequality as (xy)2xy>0\frac{(x - y)^2}{xy} > 0 shows that since (xy)2>0(x - y)^2 > 0 for all xyx \neq y, the inequality holds if and only if xy>0xy > 0.

Adım Adım Çözüm

1
Combine the fractions on the left-hand side of the target inequality
x2+y2xy>2\frac{x^2 + y^2}{xy} > 2
Finding a common denominator xyxy combines the two reciprocal ratios into a single rational expression.
2
Move all terms to one side to compare against zero
x2+y2xy2>0    x22xy+y2xy>0\frac{x^2 + y^2}{xy} - 2 > 0 \implies \frac{x^2 - 2xy + y^2}{xy} > 0
Comparing rational expressions directly to zero simplifies testing for positive or negative regions.
3
Factor the numerator into a perfect square
(xy)2xy>0\frac{(x - y)^2}{xy} > 0
Recognizing x22xy+y2x^2 - 2xy + y^2 as (xy)2(x - y)^2 isolates a term with a guaranteed non-negative property.
4
Evaluate sign conditions under the problem constraints
Because xyx \neq y, (xy)2(x - y)^2 is strictly positive. Thus, (xy)2xy>0\frac{(x - y)^2}{xy} > 0 holds if and only if xy>0xy > 0.
A quotient with a strictly positive numerator is positive if and only if its denominator is positive.

Anahtar Kavram

Question Stem Simplification via Rational Expression Factoring
Soru 449Soru

Consider the following argument: A regional hospital system plans to replace all traditional brass door handles across its facilities with handles coated in a novel antimicrobial polymer coating in order to reduce patient infection rates. Hospital administrators reason that because laboratory tests demonstrate the polymer kills 99 percent of surface bacteria within fifteen minutes of contact, installing these coated handles will significantly decrease the incidence of hospital-acquired infections.

True or False: Determining whether the routine chemical cleaning solutions used by hospital sanitation staff rapidly degrade the antimicrobial efficacy of the polymer coating upon contact constitutes a valid application of the Test of Variance for evaluating the validity of the administrators' argument.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

The statement is True. Assessing whether hospital cleaning chemicals degrade the antimicrobial polymer coating is a valid test of variance because two opposite extreme answers yield opposite logical impacts on the conclusion.
The statement is correct because the proposed evaluation directly targets a necessary condition for the real-world success of the hospital's plan. Applying the Test of Variance shows that if hospital disinfectants destroy the polymer coating, the conclusion is invalid, whereas if the disinfectants leave the coating undamaged, the premise holds in practice.

Adım Adım Çözüm

1
Identify the core argument structure
Premise: Laboratory tests show a polymer coating kills 99% of bacteria within 15 minutes. Conclusion: Installing polymer-coated door handles in hospitals will significantly decrease patient infection rates.
Understanding the premise-to-conclusion gap is required to evaluate what unstated assumptions link laboratory results to real-world outcomes.
2
Apply the two opposite extreme outcomes of the Test of Variance to the candidate evaluation question
Extreme Outcome 1: Cleaning chemicals DO rapidly degrade the polymer coating. Extreme Outcome 2: Cleaning chemicals DO NOT degrade the polymer coating.
The Test of Variance tests argument validity by checking if opposite polar responses exert opposite logical forces on the conclusion.
3
Analyze the logical impact of each extreme outcome on the conclusion
If degradation occurs rapidly, the handles lose their antibacterial properties under actual hospital protocols, causing the plan to fail (weakens the argument). If degradation does not occur, the polymer remains effective as demonstrated in labs (supports the argument).
Because one extreme outcome invalidates the plan while the opposite extreme outcome preserves its likelihood of success, the evaluated factor is crucial for assessing argument validity.

Anahtar Kavram

Evaluating Argument Validity via the Test of Variance
Tahmini Süre:2m 0s
Soru 450Soru

If xx is a real number, is xx an integer?

(1) x2+xx^2 + x is an integer.
(2) x3+x2x^3 + x^2 is an integer.

Cevabı ve açıklamayı göster

Cevap: BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

Cevap

Both statements together are sufficient to determine that xx is an integer, but neither statement alone is sufficient.
Evaluating each statement independently reveals that non-integer real numbers can produce integer values for x2+xx^2 + x or x3+x2x^3 + x^2. However, combining both statements allows us to factor x3+x2x^3 + x^2 as x(x2+x)x(x^2 + x). Setting x2+x=mx^2 + x = m and x3+x2=kx^3 + x^2 = k for integers mm and kk, we find xm=kx \cdot m = k. If m=0m = 0, xx is 0 or -1 (integers). If m0m \neq 0, x=kmx = \frac{k}{m} is a rational number. Writing x=abx = \frac{a}{b} in lowest terms and substituting it back into x2+x=mx^2 + x = m shows that bb must divide a2a^2, forcing b=1b = 1. Thus, xx must be an integer, providing a definitive affirmative answer.

Adım Adım Çözüm

1
Evaluate Statement (1) independently.
Statement (1) is INSUFFICIENT.
If x=2x = 2, then x2+x=6x^2 + x = 6, which is an integer (YES). However, if x=1+52x = \frac{-1 + \sqrt{5}}{2}, then x2+x1=0    x2+x=1x^2 + x - 1 = 0 \implies x^2 + x = 1, which is an integer, but xx is not an integer (NO). Thus, Statement (1) alone is insufficient.
2
Evaluate Statement (2) independently.
Statement (2) is INSUFFICIENT.
If x=2x = 2, then x3+x2=12x^3 + x^2 = 12, an integer (YES). If xx is the real root of x3+x2=1x^3 + x^2 = 1 (where x0.755x \approx 0.755), x3+x2x^3 + x^2 is an integer, but xx is not an integer (NO). Thus, Statement (2) alone is insufficient.
3
Evaluate Statements (1) and (2) together.
Statements (1) and (2) together are SUFFICIENT.
Let x2+x=mx^2 + x = m where mZm \in \mathbb{Z}, and x3+x2=kx^3 + x^2 = k where kZk \in \mathbb{Z}. Notice that x3+x2=x(x2+x)=xm=kx^3 + x^2 = x(x^2 + x) = x \cdot m = k. If m=0m = 0, then x2+x=0    x=0x^2 + x = 0 \implies x = 0 or x=1x = -1, both of which are integers. If m0m \neq 0, then x=kmx = \frac{k}{m}, meaning xx must be a rational number. Express x=abx = \frac{a}{b} in lowest terms, where a,bZa, b \in \mathbb{Z}, b>0b > 0, and gcd(a,b)=1\gcd(a, b) = 1. Substituting x=abx = \frac{a}{b} into x2+x=mx^2 + x = m yields a2+abb2=m    a2+ab=mb2    a2=b(mba)\frac{a^2 + ab}{b^2} = m \implies a^2 + ab = m b^2 \implies a^2 = b(mb - a). This implies that bb must divide a2a^2. Since gcd(a,b)=1\gcd(a, b) = 1, bb can only divide a2a^2 if b=1b = 1. Therefore, x=a1=ax = \frac{a}{1} = a, which means xx MUST be an integer. The answer to the question is a definitive YES.

Anahtar Kavram

Testing real vs. integer constraints and applying rational root divisibility properties in Data Sufficiency.
Tahmini Süre:2m 0s
Soru 451Soru

To reduce annual operational expenditures, the municipal water authority of Oakhaven plans to install acoustic sensor networks along its underground pipeline grid. The authority reasons that because these sensors detect acoustic frequencies generated by micro-leaks long before water breaches the surface, maintenance crews can repair small pipe fractures early, thereby significantly lowering total water loss costs and expensive emergency excavation expenses.

Which of the following, if true, most seriously weakens the municipal water authority's argument?

Cevabı ve açıklamayı göster

Cevap: Subterranean vibrations from heavy vehicle traffic and municipal transit lines in Oakhaven frequently trigger false leak alerts in the acoustic sensors, resulting in exploratory excavations that cost more than traditional emergency repairs.

Cevap

The argument is most seriously weakened by the finding that subterranean traffic vibrations cause frequent false leak alerts in acoustic sensors, prompting exploratory excavations that cost more than traditional emergency repairs.
The conclusion asserts that installing acoustic sensors will lower water loss and emergency excavation expenses. The correct answer points out that background traffic vibrations trigger false positive alerts, leading to unnecessary exploratory digs that cost more than current emergency repairs. This directly invalidates the premise that early detection leads to overall net savings on excavations.

Adım Adım Çözüm

1
Identify the conclusion and main premise of the argument.
Conclusion: Installing acoustic sensor networks will significantly lower total water loss costs and emergency excavation expenses. Premise: Sensors detect micro-leaks early, allowing early repairs.
Understanding the logical gap requires isolating what the author assumes will happen when sensors are deployed.
2
Identify the underlying unstated assumption.
The author assumes that sensor alerts will accurately indicate actionable leaks without introducing new, unforeseen operational expenses that outweigh the savings.
A weakening statement must target this link by showing why early detection via sensors will not actually result in net cost savings.
3
Evaluate the answer choices for a factor that undermines the net cost reduction.
The statement regarding false leak alerts triggered by traffic vibrations demonstrates that the sensors will generate unnecessary exploratory digs, incurring costs that exceed baseline repair expenses.
This directly counteracts the claim that total excavation and maintenance costs will decrease.

Anahtar Kavram

Weakening Causal and Plan-to-Goal Arguments
Soru 452Soru

[Tab 1: Cold-Chain Storage & Transport Protocol (2026 Revision)]
Pharmaceutical Logistics Regulatory Policy:
- Class 1 Biologics: Must be maintained at 2C2^\circ\text{C} to 8C8^\circ\text{C} during transit. Any temperature excursion above 8C8^\circ\text{C} lasting strictly more than 30 minutes triggers mandatory thermal quarantine. A 15%15\% surcharge is assessed on the shipment's base transport fee for quarantined items, unless the freight carrier holds a Tier-A Thermal Compliance Certification.
- Class 2 Biologics: Must be maintained below 20C-20^\circ\text{C}. Any excursion above 20C-20^\circ\text{C} invalidates the shipment unless a secondary liquid nitrogen (LN2) backup system was logged active throughout the entire duration of the excursion.

[Tab 2: Q2 Carrier Audit Log (Apex Cargo Services)]
- Shipment #801: Class 1 Biologics; Base Transport Fee: $12,000\$12,000; Temp Excursion: Reached 10C10^\circ\text{C} for 45 minutes; Secondary LN2 Backup: N/A; Carrier Certification: Tier-B Thermal Compliance.
- Shipment #802: Class 2 Biologics; Base Transport Fee: $25,000\$25,000; Temp Excursion: Reached 15C-15^\circ\text{C} for 15 minutes; Secondary LN2 Backup: Logged Active; Carrier Certification: Tier-A Thermal Compliance.
- Shipment #803: Class 1 Biologics; Base Transport Fee: $18,000\$18,000; Temp Excursion: Reached 9C9^\circ\text{C} for 20 minutes; Secondary LN2 Backup: N/A; Carrier Certification: Tier-B Thermal Compliance.

Statement: Based on the provided protocol and carrier audit log, Shipment #801 is subject to a mandatory $1,800\$1,800 thermal surcharge, whereas Shipment #803 incurs no thermal surcharge.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
Synthesizing the rules in Tab 1 with the audit log in Tab 2 confirms that Shipment #801 exceeds the 30-minute excursion threshold (45 min>30 min45\text{ min} > 30\text{ min}) for Class 1 Biologics, subjecting its non-Tier-A carrier to a 15%15\% surcharge (0.15×$12,000=$1,8000.15 \times \$12,000 = \$1,800). Meanwhile, Shipment #803's excursion lasted only 20 minutes, falling below the 30-minute cutoff required to trigger a surcharge. Therefore, the statement is completely accurate.

Adım Adım Çözüm

1
Analyze Shipment #801 against Class 1 Biologics policy.
Shipment #801 had an excursion to 10C10^\circ\text{C} for 45 minutes. Because 10C>8C10^\circ\text{C} > 8^\circ\text{C} and 45 minutes >30> 30 minutes, thermal quarantine is triggered.
Tab 1 specifies that Class 1 excursions above 8C8^\circ\text{C} lasting more than 30 minutes require quarantine.
2
Calculate the surcharge for Shipment #801.
Carrier certification is Tier-B, so the exemption does not apply. Surcharge = 15%×$12,000=$1,80015\% \times \$12,000 = \$1,800.
Tab 1 states a 15%15\% base fee surcharge applies unless the carrier holds Tier-A certification.
3
Analyze Shipment #803 against Class 1 Biologics policy.
Shipment #803 had an excursion to 9C9^\circ\text{C} for 20 minutes. Since 20 minutes 30\le 30 minutes, quarantine and surcharges are not triggered.
The duration threshold of 30 minutes was not exceeded.
4
Synthesize results to evaluate the full statement.
Shipment #801 incurs $1,800\$1,800 and Shipment #803 incurs $0\$0. The statement is True.
Both conditions stated in the prompt evaluate to true.

Anahtar Kavram

Multi-source policy application and logical condition evaluation across independent tabular data.
Soru 453Soru

If xx and yy are positive real numbers, is xx an integer?

(1) x+yx + y is an integer, and x2+xyx^2 + xy is an integer.
(2) xyx - y is an integer, and x2y2x^2 - y^2 is an integer.

Cevabı ve açıklamayı göster

Cevap: Statements (1) and (2) TOGETHER are NOT sufficient.

Cevap

Statements (1) and (2) together are not sufficient to determine whether xx is an integer.
The correct option identifies that statements (1) and (2) together are not sufficient. Testing half-integers such as x=2.5x = 2.5 and y=1.5y = 1.5 shows that all given conditions (x+y=4x+y=4, x2+xy=10x^2+xy=10, xy=1x-y=1, x2y2=4x^2-y^2=4) are integers while xx is not an integer. Conversely, x=3x = 3 and y=1y = 1 satisfies all conditions with an integer xx. Thus, a definitive Yes/No answer cannot be determined.

Adım Adım Çözüm

1
Analyze Statement (1) independently.
Statement (1) states that x+y=kx + y = k (where kk is an integer) and x2+xy=x(x+y)=mx^2 + xy = x(x+y) = m (where mm is an integer). Thus, xk=m    x=mkx \cdot k = m \implies x = \frac{m}{k}. Since mm and kk are integers, xx is rational, but not necessarily an integer. For example, if x=1.5x = 1.5 and y=0.5y = 0.5, then x+y=2x + y = 2 (integer) and x2+xy=1.5(2)=3x^2 + xy = 1.5(2) = 3 (integer), but x=1.5x = 1.5 is not an integer. If x=2x = 2 and y=1y = 1, then x+y=3x + y = 3 and x2+xy=6x^2 + xy = 6, and x=2x = 2 is an integer. Thus, Statement (1) alone is INSUFFICIENT.
Variable xx is only constrained to be a rational number mk\frac{m}{k}, which may or may not be an integer.
2
Analyze Statement (2) independently.
Statement (2) states that xy=dx - y = d (where dd is an integer) and x2y2=(xy)(x+y)=px^2 - y^2 = (x-y)(x+y) = p (where pp is an integer). Thus d(x+y)=p    x+y=pdd(x+y) = p \implies x+y = \frac{p}{d}. Then 2x=(x+y)+(xy)=pd+d=p+d2d    x=p+d22d2x = (x+y) + (x-y) = \frac{p}{d} + d = \frac{p + d^2}{d} \implies x = \frac{p + d^2}{2d}. If x=2.5x = 2.5 and y=1.5y = 1.5, then xy=1x - y = 1 (integer) and x2y2=6.252.25=4x^2 - y^2 = 6.25 - 2.25 = 4 (integer), but x=2.5x = 2.5 is not an integer. If x=2x = 2 and y=1y = 1, xy=1x - y = 1 and x2y2=3x^2 - y^2 = 3, and x=2x = 2 is an integer. Thus, Statement (2) alone is INSUFFICIENT.
Variable xx is constrained to a rational form with denominator 2d2d, which allows non-integer values.
3
Analyze Statements (1) and (2) combined.
Combining both statements gives x+y=kx + y = k (integer) and xy=dx - y = d (integer). Adding these yields 2x=k+d2x = k + d, so 2x2x must be an integer. This means xx can be an integer or a half-integer (e.g., 2.52.5). Testing x=2.5x = 2.5 and y=1.5y = 1.5: both are positive real numbers; x+y=4x + y = 4 (integer); x2+xy=2.5(4)=10x^2 + xy = 2.5(4) = 10 (integer); xy=1x - y = 1 (integer); and x2y2=6.252.25=4x^2 - y^2 = 6.25 - 2.25 = 4 (integer). Here xx is NOT an integer. Testing x=3x = 3 and y=1y = 1: both are positive real numbers; x+y=4x + y = 4 (integer); x2+xy=3(4)=12x^2 + xy = 3(4) = 12 (integer); xy=2x - y = 2 (integer); and x2y2=91=8x^2 - y^2 = 9 - 1 = 8 (integer). Here xx IS an integer. Because both 'Yes' and 'No' answers are possible under all conditions, Statements (1) and (2) together are INSUFFICIENT.
The system of equations allows xx to be a half-integer (such as 2.52.5), satisfying all integer conditions of both statements without requiring xx itself to be an integer.

Anahtar Kavram

Evaluating implicit non-integer constraints and system degree in Data Sufficiency questions.
Soru 454Soru

If kk is a positive real number, is kk an integer?

(1) k\sqrt{k} is an integer.
(2) k24kk^2 - 4k is an integer.

Cevabı ve açıklamayı göster

Cevap: Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

Cevap

Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (1) alone is sufficient because if the square root of kk is an integer mm, then k=m2k = m^2, which is guaranteed to be an integer. Statement (2) alone is not sufficient because k24kk^2 - 4k can equal an integer when k=4k = 4 (an integer) or when k=2+5k = 2 + \sqrt{5} (a non-integer). Therefore, only Statement (1) is sufficient.

Adım Adım Çözüm

1
Evaluate Statement (1) independently.
If k=m\sqrt{k} = m where mm is an integer, then k=m2k = m^2. Since mm is an integer, m2m^2 must also be an integer. Thus, kk is definitely an integer (Yes).
The square of any integer is always an integer, so Statement (1) is sufficient.
2
Evaluate Statement (2) independently.
Let k24k=nk^2 - 4k = n, where nn is an integer. If n=0n = 0, then k(k4)=0    k=4k(k - 4) = 0 \implies k = 4 (an integer). If n=1n = 1, then k24k1=0    k=2+5k^2 - 4k - 1 = 0 \implies k = 2 + \sqrt{5} (not an integer).
Since kk can be either an integer or a non-integer, Statement (2) does not provide a definitive Yes/No answer and is not sufficient.

Anahtar Kavram

Algebraic definitions of integers versus real numbers in Data Sufficiency
Tahmini Süre:2m 0s
Soru 455Soru

The table below details operational telemetry for eight municipal battery energy storage system (BESS) microgrid zones during 2025:

Zone CodeBattery Capacity (MWh)Annual Energy Discharged (GWh)Peak Efficiency (%)Unplanned Maintenance (Hours)
Zone Alpha12043.292.548
Zone Beta20084.095.012
Zone Gamma15051.089.072
Zone Delta300117.094.224
Zone Epsilon8026.491.096
Zone Zeta250105.096.518
Zone Eta18059.488.560
Zone Theta22085.893.036

Consider the following three independent statements:

I. If the zones are sorted in ascending order by Battery Capacity (MWh), the median Peak Efficiency (%) of the lower half of the sorted zones is greater than 90.5%90.5\%.
II. The average annual energy discharged per MWh of battery capacity across the three zones with the fewest unplanned maintenance hours is strictly greater than 0.40 GWh per MWh0.40\text{ GWh per MWh}.
III. Among the zones with a Peak Efficiency of at least 92.0%92.0\%, exactly four zones recorded fewer than 4040 unplanned maintenance hours.

Based on the table provided, is the evaluation that Statement I is False, Statement II is True, and Statement III is True correct?

Cevabı ve açıklamayı göster

Cevap: True

Cevap

The overall evaluation is True because Statement I is False, Statement II is True, and Statement III is True.
Evaluating all three statements shows that Statement I is False (90.0%90.5%90.0\% \ngtr 90.5\%), Statement II is True (0.408>0.400.408 > 0.40), and Statement III is True (44 zones meet both criteria). Thus, the proposed outcome (False, True, True) accurately describes the dataset.

Adım Adım Çözüm

1
Evaluate Statement I by sorting zones by Battery Capacity and finding the median Peak Efficiency of the lower half.
Sorted capacity order: Epsilon (8080), Alpha (120120), Gamma (150150), Eta (180180), Beta (200200), Theta (220220), Zeta (250250), Delta (300300). Lower half: Epsilon (91.0%91.0\%), Alpha (92.5%92.5\%), Gamma (89.0%89.0\%), Eta (88.5%88.5\%). Efficiencies sorted: 88.5%88.5\%, 89.0%89.0\%, 91.0%91.0\%, 92.5%92.5\%. Median = 89.0%+91.0%2=90.0%\frac{89.0\% + 91.0\%}{2} = 90.0\%. Since 90.0%90.5%90.0\% \le 90.5\%, Statement I is False.
Determines whether Statement I is correctly classified as False.
2
Evaluate Statement II by identifying the three zones with the minimum unplanned maintenance hours and computing their aggregate discharge per MWh of capacity.
Fewest maintenance hours: Zone Beta (12 hrs12\text{ hrs}), Zone Zeta (18 hrs18\text{ hrs}), Zone Delta (24 hrs24\text{ hrs}). Sum of energy discharged = 84.0+105.0+117.0=306.0 GWh84.0 + 105.0 + 117.0 = 306.0\text{ GWh}. Sum of capacity = 200+250+300=750 MWh200 + 250 + 300 = 750\text{ MWh}. Rate = 306.0750=0.408 GWh/MWh\frac{306.0}{750} = 0.408\text{ GWh/MWh}. Since 0.408>0.400.408 > 0.40, Statement II is True.
Determines whether Statement II is correctly classified as True.
3
Evaluate Statement III by filtering zones with Peak Efficiency 92.0%\ge 92.0\% and counting how many have unplanned maintenance hours under 4040.
Zones with Peak Efficiency 92.0%\ge 92.0\%: Alpha (92.5%92.5\%, 48 hrs48\text{ hrs}), Beta (95.0%95.0\%, 12 hrs12\text{ hrs}), Delta (94.2%94.2\%, 24 hrs24\text{ hrs}), Zeta (96.5%96.5\%, 18 hrs18\text{ hrs}), Theta (93.0%93.0\%, 36 hrs36\text{ hrs}). Those with maintenance hours <40< 40: Beta, Delta, Zeta, Theta (44 zones). Statement III is True.
Determines whether Statement III is correctly classified as True.

Anahtar Kavram

Multi-Statement Boolean Evaluation in Tabular Data
Soru 456Soru

The table below presents operational metrics for municipal EV charging infrastructure across six urban transit sectors in 2025.

Transit SectorTotal EV StationsFast-Charging StationsTotal Energy Delivered (MWh)Commercial Fleet Usage (MWh)
Sector Alpha120364,8001,440
Sector Beta200807,5003,000
Sector Gamma150455,0001,250
Sector Delta90543,6002,160
Sector Epsilon160326,4001,600
Sector Zeta80482,8001,960

Evaluate the following statement as True or False based on the information provided:

Among all transit sectors where fast-charging stations constitute at least 40%40\% of the total EV stations, the overall proportion of total energy delivered that was consumed by commercial fleets is greater than 50%50\%.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
The qualifying sectors (Beta, Delta, Zeta) have a combined commercial fleet energy consumption of 7,1207,120 MWh out of 13,90013,900 MWh total energy delivered, yielding an overall percentage of 51.22%51.22\%, which exceeds 50%50\%.

Adım Adım Çözüm

1
Calculate the fast-charging station percentage for each transit sector to filter qualifying sectors.
Sectors Beta (40%40\%), Delta (60%60\%), and Zeta (60%60\%) qualify with fast-charging proportions 40%\ge 40\%.
Filtering rows based on a specified threshold is required before aggregating cross-column data.
2
Sum the total energy delivered and commercial fleet energy usage for the qualifying sectors.
Total energy delivered = 7,500+3,600+2,800=13,9007,500 + 3,600 + 2,800 = 13,900 MWh. Commercial fleet usage = 3,000+2,160+1,960=7,1203,000 + 2,160 + 1,960 = 7,120 MWh.
Calculating weighted overall percentages requires finding the sum of part values over the sum of whole values.
3
Compute the overall commercial fleet energy percentage for the qualifying sectors.
\frac{7,120}{13,900} \approx 51.22\%, which is strictly greater than 50\%.
Demonstrates whether the statement's inequality condition holds true.

Anahtar Kavram

Weighted Aggregated Percentage Calculation from Filtered Table Rows
Soru 457Soru

Passage:
Recent genomic sequencing of Asgard archaea inhabiting deep-sea hydrothermal vent sediments has provided crucial empirical evidence regarding the origins of eukaryotic cellular complexity. Unlike all previously characterized prokaryotes, Asgard archaea possess functional genes encoding proteins structurally analogous to eukaryotic actin filaments and endosomal sorting complexes. Evolutionary biologists initially hypothesized that eukaryotic progenitor cells acquired these complex structural proteins exclusively after the primary endosymbiotic engulfment of an alpha-proteobacterium—the event that gave rise to mitochondria.

However, the presence of these 'eukaryotic signature proteins' (ESPs) in uncultivated Asgard lineages demonstrates that the structural machinery required for membrane remodeling and cellular engulfment evolved prior to mitochondrial acquisition. Crucially, phylogenetic analyses indicate that while Asgard lineages possess ESPs, they lack the specific lipid synthesis pathways necessary to construct the ester-linked phospholipid membranes characteristic of eukaryotes, retaining instead the ether-linked isoprenoid membranes typical of archaea. Consequently, researchers infer that the transition from ether-linked to ester-linked membrane chemistry occurred after the primitive host cell established stable endosymbiosis with the mitochondrial ancestor, rather than during the initial structural diversification of pre-eukaryotic archaea.

Based on the premises in the passage, evaluate whether the following statement is True or False:
"The evolutionary development of membrane remodeling machinery in the ancestral host lineage preceded the chemical transition from ether-linked to ester-linked membrane lipids."

Cevabı ve açıklamayı göster

Cevap: True

Cevap

The statement is True.
The statement is True because the passage sets up a strict chronological sequence using mitochondrial acquisition as a benchmark: membrane remodeling machinery evolved before mitochondrial acquisition, while the transition to ester-linked lipids occurred after. Thus, membrane remodeling machinery evolved prior to the lipid transition.

Adım Adım Çözüm

1
Identify the premise regarding the timing of membrane remodeling machinery.
The passage states that structural machinery for membrane remodeling (eukaryotic signature proteins) evolved prior to mitochondrial acquisition.
This establishes the first temporal benchmark on the evolutionary timeline.
2
Identify the premise regarding the timing of the lipid chemistry transition.
The passage states that the transition from ether-linked to ester-linked membrane chemistry occurred after stable endosymbiosis with the mitochondrial ancestor was established.
This establishes the second temporal benchmark on the evolutionary timeline.
3
Synthesize the temporal relationship between the two events.
Since membrane remodeling evolved before mitochondrial acquisition, and the lipid chemistry transition occurred after mitochondrial acquisition, membrane remodeling necessarily preceded the lipid chemistry transition.
Logically combining 'Event A < Mitochondrial Acquisition' and 'Mitochondrial Acquisition < Event B' proves 'Event A < Event B'.

Anahtar Kavram

Synthesizing multi-premise temporal relationships to draw valid logical deductions.
Soru 458Soru

In 2025, an architectural design firm divided its working hours among commercial, residential, and municipal projects. Commercial projects accounted for 0.400.40 of the total hours. Of the remaining hours, 512\frac{5}{12} were spent on residential projects, and the rest were spent on municipal projects.

In 2026, the firm's total working hours increased by 25%25\%. Commercial project hours decreased by 15%15\%, while residential project hours increased by 40%40\%. By what percent did the number of hours spent on municipal projects increase from 2025 to 2026?

Cevabı ve açıklamayı göster

Cevap: 60

Cevap

The number of hours spent on municipal projects increased by 60%60\%.
By setting the total initial hours to a variable TT (or a convenient constant like 100100), we find that in 2025, commercial projects comprised 0.40T0.40T, residential comprised 512×0.60T=0.25T\frac{5}{12} \times 0.60T = 0.25T, and municipal comprised 0.35T0.35T. In 2026, total hours rose to 1.25T1.25T, commercial dropped to 0.34T0.34T, and residential rose to 0.35T0.35T, leaving 0.56T0.56T for municipal. The percent increase in municipal hours is 0.56T0.35T0.35T=0.210.35=60%\frac{0.56T - 0.35T}{0.35T} = \frac{0.21}{0.35} = 60\%.

Adım Adım Çözüm

1
Determine the baseline breakdown of working hours for 2025 in terms of total hours TT.
Commercial hours = 0.40T0.40T, Residential hours = 0.25T0.25T, Municipal hours = 0.35T0.35T.
Commercial is given as 0.40T0.40T. The remaining fraction 0.60T0.60T is split such that 512×0.60T=0.25T\frac{5}{12} \times 0.60T = 0.25T goes to residential, leaving 0.60T0.25T=0.35T0.60T - 0.25T = 0.35T for municipal.
2
Calculate the updated working hours for each category in 2026.
Total hours = 1.25T1.25T, Commercial hours = 0.34T0.34T, Residential hours = 0.35T0.35T.
A 25%25\% total increase yields 1.25T1.25T. A 15%15\% decrease in commercial hours yields 0.40T×0.85=0.34T0.40T \times 0.85 = 0.34T. A 40%40\% increase in residential hours yields 0.25T×1.40=0.35T0.25T \times 1.40 = 0.35T.
3
Find the municipal project hours for 2026 by subtracting commercial and residential hours from total 2026 hours.
Municipal hours (2026) = 0.56T0.56T.
Municipal hours in 2026 equal 1.25T0.34T0.35T=0.56T1.25T - 0.34T - 0.35T = 0.56T.
4
Compute the percent change in municipal project hours from 2025 to 2026.
Percent Increase = 60%60\%.
Percent increase is Municipal2026Municipal2025Municipal2025×100%=0.56T0.35T0.35T×100%=0.210.35×100%=60%\frac{\text{Municipal}_{2026} - \text{Municipal}_{2025}}{\text{Municipal}_{2025}} \times 100\% = \frac{0.56T - 0.35T}{0.35T} \times 100\% = \frac{0.21}{0.35} \times 100\% = 60\%.

Anahtar Kavram

Multi-step percentage change and fraction-decimal conversions
Tahmini Süre:2m 0s
Soru 459Soru

At the start of a fiscal year, a sovereign wealth fund allocated its capital into three asset classes: Stocks, Bonds, and Commodities. Exactly 0.400.40 of the total capital was allocated to Stocks. Of the remaining capital, 13\frac{1}{3} was allocated to Bonds and the rest was allocated to Commodities. Over the course of the fiscal year, the value of Stocks increased by 15%15\% and the value of Bonds decreased by 10%10\%. If the total value of the fund increased by 5%5\% by the end of the fiscal year, by what percent did the value of Commodities change?

Cevabı ve açıklamayı göster

Cevap: 2.5

Cevap

The value of Commodities increased by 2.5%2.5\%.
By setting the initial total capital to VV, the initial values are Stocks = 0.40V0.40V, Bonds = 13(0.60V)=0.20V\frac{1}{3}(0.60V) = 0.20V, and Commodities = 0.60V0.20V=0.40V0.60V - 0.20V = 0.40V. Applying the percentage changes gives final values of Stocks = 0.46V0.46V, Bonds = 0.18V0.18V, and Total Fund = 1.05V1.05V. The final Commodities value is 1.05V0.64V=0.41V1.05V - 0.64V = 0.41V. The percent change in Commodities is 0.41V0.40V0.40V×100%=2.5%\frac{0.41V - 0.40V}{0.40V} \times 100\% = 2.5\%.

Adım Adım Çözüm

1
Determine initial asset allocations as proportions of total capital VV
Stocks (S0S_0) = 0.40V0.40V, Bonds (B0B_0) = 0.20V0.20V, Commodities (C0C_0) = 0.40V0.40V
Stocks take 0.40V0.40V, leaving 0.60V0.60V. Bonds take 13\frac{1}{3} of 0.60V=0.20V0.60V = 0.20V, leaving 0.40V0.40V for Commodities.
2
Compute final values for Stocks, Bonds, and Total Fund after percentage changes
S1=0.46VS_1 = 0.46V, B1=0.18VB_1 = 0.18V, and Total Fund V1=1.05VV_1 = 1.05V
Stocks increase by 15%15\% (0.40V×1.15=0.46V0.40V \times 1.15 = 0.46V), Bonds decrease by 10%10\% (0.20V×0.90=0.18V0.20V \times 0.90 = 0.18V), and the total fund grows by 5%5\% (1.05V1.05V).
3
Calculate the end-of-year value of Commodities
C1=0.41VC_1 = 0.41V
Subtract final Stocks and Bonds from total fund: C1=1.05V(0.46V+0.18V)=0.41VC_1 = 1.05V - (0.46V + 0.18V) = 0.41V.
4
Calculate the percent change of Commodities relative to its initial value
2.5%2.5\% increase
Percent change =0.41V0.40V0.40V×100%=0.010.40×100%=2.5%= \frac{0.41V - 0.40V}{0.40V} \times 100\% = \frac{0.01}{0.40} \times 100\% = 2.5\%.

Anahtar Kavram

Weighted percentage change and fractional portion modeling
Tahmini Süre:1m 40s
Soru 460Soru

A commercial coffee roastery prepares a batch of specialty coffee beans containing Arabica, Robusta, and Liberica beans. Initially, Arabica beans make up 0.500.50 of the total weight of the batch, Robusta beans make up 310\frac{3}{10} of the total weight, and Liberica beans make up the remaining weight. After a specialized roasting process, the weight of the Arabica beans decreases by 10%10\%, the weight of the Robusta beans decreases by 50%50\%, and the weight of the Liberica beans remains unchanged. What percent of the final total weight of the coffee batch is made up of Liberica beans?

Cevabı ve açıklamayı göster

Cevap: 25

Cevap

25%
To find the percentage of Liberica beans in the final mixture, first determine the initial weight breakdown assuming a total weight of 100 units: Arabica is 50 units, Robusta is 30 units, and Liberica is 20 units. After roasting, Arabica weight decreases by 10% to 45 units, Robusta weight decreases by 50% to 15 units, and Liberica weight stays at 20 units. The new total weight is 45 + 15 + 20 = 80 units. The proportion of Liberica in the final batch is 20 out of 80 units, which equals 1/4 or 25%.

Adım Adım Çözüm

1
Find the initial fractional and percentage composition of the coffee blend.
Arabica accounts for 50% (0.50), Robusta accounts for 30% (3/10), and Liberica accounts for 20% (1 - 0.50 - 0.30 = 0.20).
The sum of all components in the initial blend must equal 1 (or 100%).
2
Assume an initial reference weight of 100 units to represent the batch.
Initial Arabica weight = 50 units, initial Robusta weight = 30 units, and initial Liberica weight = 20 units.
Using a convenient base value like 100 simplifies multi-step percentage change calculations without loss of generality.
3
Calculate the post-roasting weight for each component.
New Arabica weight = 50 * (1 - 0.10) = 45 units. New Robusta weight = 30 * (1 - 0.50) = 15 units. New Liberica weight = 20 units.
Apply the respective percentage decreases to each individual component weight.
4
Determine the new total weight of the batch.
Total final weight = 45 + 15 + 20 = 80 units.
The final total weight is the sum of the remaining weights of all three bean types.
5
Compute the final percentage of Liberica beans.
(20 / 80) * 100% = 25%.
Divide the final weight of Liberica beans by the final total weight of the batch and convert to a percentage.

Anahtar Kavram

Combining initial fractions and percentages to compute multi-step composition changes
ÖncekiSayfa 23 / 110Sonraki
Tüm alıştırma soruları — GMAT | Examkin