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Question 501Question

In a published civil services merit list, Rohan is ranked 14th14^{\text{th}} from the top, while Seema is ranked 33rd33^{\text{rd}} from the bottom. After a re-evaluation of marks, Rohan and Seema interchange their positions, resulting in Rohan becoming 48th48^{\text{th}} from the top. A third candidate, Amit, holds a rank exactly halfway between Rohan's new position and Seema's new position. If 66 candidates ranked above Amit withdraw their candidature and 44 new candidates are placed below Amit in the updated list, what is Amit's final rank from the bottom of the modified merit list?

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Answer: 54

Answer

Amit's final rank from the bottom of the modified merit list is 54.
Seema's dual information (48th48^{\text{th}} from top and 33rd33^{\text{rd}} from bottom) gives an initial total of 80 candidates. Amit's midpoint position between 14th14^{\text{th}} and 48th48^{\text{th}} is 31st31^{\text{st}} from top, placing 49 candidates below him. Accounting for 6 withdrawals above and 4 additions below leaves 53 candidates below Amit, establishing his final rank as 54th54^{\text{th}} from the bottom.

Step-by-Step Solution

1
Find total candidates in the original merit list using the interchange data.
Total candidates N = 80
When Rohan and Seema interchange positions, Rohan occupies Seema's original spot (48th48^{\text{th}} from top). Since Seema was 33rd33^{\text{rd}} from bottom, N=48+331=80N = 48 + 33 - 1 = 80.
2
Calculate Amit's initial rank from the top.
Amit's initial top rank = 31st
Amit is positioned halfway between Seema's new position (14th14^{\text{th}} from top) and Rohan's new position (48th48^{\text{th}} from top), so rank = (14+48)/2=31st(14 + 48) / 2 = 31^{\text{st}}.
3
Find initial counts of candidates ranked above and below Amit.
30 candidates above, 49 candidates below
With a top rank of 31st31^{\text{st}} out of 80, there are 311=3031 - 1 = 30 candidates above Amit and 8031=4980 - 31 = 49 candidates below Amit.
4
Adjust counts based on candidate withdrawals and additions.
24 candidates above, 53 candidates below
Subtract 6 from candidates above (306=2430 - 6 = 24) and add 4 to candidates below (49+4=5349 + 4 = 53).
5
Calculate Amit's revised rank from the bottom.
54th from the bottom
The rank from the bottom equals (candidates below + 1), which gives 53+1=5453 + 1 = 54.

Key Concept

Dual Rank Position Interchange, Midpoint Computation, and Dynamic List Adjustment
Estimated Time:2m 30s
Question 502Question

In a district administration office, a survey of 120120 officers was conducted regarding their proficiency in using three government portals: e-Office (EE), CPGRAMS (CC), and GeM (GG). The survey revealed that 6565 officers are proficient in e-Office, 5555 in CPGRAMS, and 5050 in GeM. Furthermore, 2525 officers are proficient in both e-Office and CPGRAMS, 2020 in both CPGRAMS and GeM, and 2222 in both e-Office and GeM. If 1010 officers are proficient in all three portals, how many officers are proficient in none of these three portals?

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Answer: 7

Answer

The number of officers proficient in none of the three portals is 7.
The total number of officers in at least one portal is calculated using ECG=(65+55+50)(25+20+22)+10=113|E \cup C \cup G| = (65 + 55 + 50) - (25 + 20 + 22) + 10 = 113. Subtracting this from the total group of 120120 gives 120113=7120 - 113 = 7 officers in none of the portals.

Step-by-Step Solution

1
Apply the Principle of Inclusion-Exclusion for three sets to find the total number of officers proficient in at least one portal.
ECG=E+C+GECCGEG+ECG|E \cup C \cup G| = |E| + |C| + |G| - |E \cap C| - |C \cap G| - |E \cap G| + |E \cap C \cap G|
Overlapping regions must be subtracted to prevent double counting, and the central triple intersection must be added back because it is subtracted three times.
2
Substitute the given numerical values into the formula.
ECG=65+55+50252022+10=17067+10=113|E \cup C \cup G| = 65 + 55 + 50 - 25 - 20 - 22 + 10 = 170 - 67 + 10 = 113
Calculating the total number of officers belonging to at least one category.
3
Subtract the number of officers proficient in at least one portal from the total officer population.
Number in none =120113=7= 120 - 113 = 7
Officers outside all three sets represent the complement of the union set.

Key Concept

Principle of Inclusion-Exclusion for 3 overlapping sets
Question 503Question

If 1st January 2004 was a Thursday, what day of the week was 1st January 2005?

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Answer: Saturday; saturday

Answer

Saturday
The correct answer is Saturday. The year 2004 is a leap year containing 366 days. Since the time period from 1st January 2004 to 1st January 2005 includes February 29th, there are 2 odd days. Advancing 2 days from Thursday results in Saturday.

Step-by-Step Solution

1
Determine if the year 2004 is a leap year.
2004 is divisible by 4, so it is a leap year containing 366 days.
Leap years include an extra day (29th February).
2
Calculate the number of odd days between 1st January 2004 and 1st January 2005.
366 days divided by 7 equals 52 weeks and 2 odd days (366(mod7)=2366 \pmod 7 = 2).
Full weeks do not change the day of the week, so only the remainder (odd days) shifts the day.
3
Advance the given day by the number of odd days.
Thursday + 2 days = Saturday.
Adding 2 odd days to Thursday moves the day forward to Saturday.

Key Concept

Calculating day of the week shifts across leap years using odd days
Question 504Question

Five public welfare projects—Electrification, Reforestation, Sanitation, Transport, and Water Supply—are scheduled for administrative approval from 1st to 5th based on the following conditions:
- Water Supply is approved immediately after Electrification.
- Reforestation is approved before Sanitation, but after Transport.
- Sanitation is approved before Electrification.

Arrange the five projects in the correct sequential order of their approval from 1st to 5th.

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Answer

The correct sequence of project approval from 1st to 5th is Transport, Reforestation, Sanitation, Electrification, and Water Supply.
Following the clues sequentially: Transport precedes Reforestation, which precedes Sanitation. Sanitation precedes Electrification, and Water Supply immediately follows Electrification. This establishes a unique deterministic order from 1st to 5th: Transport, Reforestation, Sanitation, Electrification, and Water Supply.

Step-by-Step Solution

1
Identify adjacent block constraints.
Water Supply immediately follows Electrification, creating the fixed block (Electrification → Water Supply).
The condition explicitly states Water Supply is approved immediately after Electrification.
2
Determine relative ordering among Transport, Reforestation, and Sanitation.
The relative order is Transport → Reforestation → Sanitation.
Reforestation is after Transport and before Sanitation.
3
Connect the relative order to the adjacent block.
Sanitation is approved before Electrification, yielding the sequence: Transport → Reforestation → Sanitation → Electrification → Water Supply.
Sanitation must precede the Electrification-Water Supply block, uniquely determining all 5 positions.

Key Concept

Linear Positional Ordering and Constraint Satisfaction
Estimated Time:1m 30s
Question 505Question

If the six-digit number 45231x45231x is completely divisible by 99, what is the value of the digit xx?

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Answer: 3

Answer

3
According to the divisibility rule for 9, a number is divisible by 9 if the sum of its digits is a multiple of 9. For the number 45231x45231x, the sum of the digits is 4+5+2+3+1+x=15+x4 + 5 + 2 + 3 + 1 + x = 15 + x. The smallest multiple of 9 that is greater than or equal to 15 is 18. Setting 15+x=1815 + x = 18 gives x=3x = 3.

Step-by-Step Solution

1
Find the sum of the known digits in the given number.
4+5+2+3+1=154 + 5 + 2 + 3 + 1 = 15
The divisibility rule for 9 requires analyzing the sum of all digits.
2
Formulate the condition for divisibility by 9.
15+x15 + x must be a multiple of 9.
Including the unknown unit digit xx, the total digit sum is 15+x15 + x.
3
Solve for the single-digit integer xx where 0x90 \le x \le 9.
x=3x = 3
The smallest multiple of 9 greater than or equal to 15 is 18, giving 15+x=1815 + x = 18, so x=3x = 3.

Key Concept

Divisibility Rule for 9

Alternative Method

Dividing 452,310 by 9 yields 50,256 with a remainder of 6. To make the number divisible by 9, the remaining amount needed is 96=39 - 6 = 3, so the unit digit xx must be 3.
Estimated Time:45s
Question 506Question

In a state administrative audit of 300300 urban development projects, participation across three infrastructure domains—Sanitation (SS), Transport (TT), and Green Space (GG)—was analyzed. The audit revealed that 145145 projects involve Sanitation, 135135 involve Transport, and 125125 involve Green Space. Exactly 7070 projects involve precisely two domains, while 2020 projects involve all three domains. Furthermore, 4545 projects involve both Sanitation and Transport, and 3535 projects involve both Transport and Green Space. Which of the following statements are correct? (Select all correct options.)

Select all that apply

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Answer: Exactly 7070 projects are dedicated exclusively to Sanitation.; The total number of projects involving at least two domains is 9090.; The number of projects involving both Green Space and Sanitation, but not Transport, is 3030.

Answer

The statements asserting that exactly 70 projects are dedicated exclusively to Sanitation, that 90 projects involve at least two domains, and that 30 projects involve both Green Space and Sanitation but not Transport are all correct.
The three correct options accurately reflect the regional values obtained from set decomposition: exclusive Sanitation projects equal 70, projects in two or more domains total 90 (70 + 20), and projects in Green Space and Sanitation only total 30.

Step-by-Step Solution

1
Calculate the regions involving exactly two domains
Sanitation and Transport only = 4520=2545 - 20 = 25; Transport and Green Space only = 3520=1535 - 20 = 15. Green Space and Sanitation only = 70(25+15)=3070 - (25 + 15) = 30.
The intersection of two sets includes the triple intersection of all three sets.
2
Calculate single-domain exclusive regions
Sanitation only = 145(25+30+20)=70145 - (25 + 30 + 20) = 70; Transport only = 135(25+15+20)=75135 - (25 + 15 + 20) = 75; Green Space only = 125(30+15+20)=60125 - (30 + 15 + 20) = 60.
Subtracting all overlapping two-set and three-set regions from each total set size isolates the single-domain counts.
3
Calculate projects in at least two domains
Projects in at least two domains = (Exactly 2 domains) + (All 3 domains) = 70+20=9070 + 20 = 90.
'At least two' is the union of the exactly two and exactly three regions.
4
Calculate total union and unaffiliated projects
Total in at least one domain = 70+75+60+25+15+30+20=29570 + 75 + 60 + 25 + 15 + 30 + 20 = 295. Unaffiliated projects = 300295=5300 - 295 = 5.
Subtracting the union of all three sets from the total project pool yields the count of elements outside all sets.

Key Concept

Three-Set Venn Diagram Region Decomposition and Inclusion-Exclusion Principle
Question 507Question

Consider the following statements regarding administrative policy and environmental developments in an agricultural district:

Statement I: The district administration implemented a strict mandate requiring drip irrigation systems for all water-intensive commercial crops.
Statement II: Groundwater depletion rates in the district registered a 25% decrease over the subsequent three years.
Statement III: Surrounding river basins experienced severe seasonal flooding due to unseasonal upstream torrential rainfall.

Based on logical cause-and-effect reasoning, which of the following statements are correct?

Select all that apply

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Answer: Statement I acts as a direct cause, and Statement II represents its logical effect.; Statement III is an independent event driven by natural weather phenomena and is not an effect of Statement I.

Answer

The statements establishing that Statement I is a direct cause of Statement II, and that Statement III represents an independent event driven by natural phenomena, are both correct.
The evaluation identifying the drip irrigation mandate as the cause and the reduced depletion rate as its effect is valid because conserving agricultural water directly leads to reduced groundwater extraction. Furthermore, recognizing the upstream flood as an independent meteorological event is correct because local farming mandates do not influence regional rainfall patterns.

Step-by-Step Solution

1
Analyze the temporal and logical link between Statement I and Statement II.
Statement I (drip irrigation mandate) precedes and directly provides the mechanism for Statement II (reduction in groundwater depletion rate). Thus, Statement I is the cause and Statement II is the effect.
Policy interventions promoting water conservation logically lead to reduced resource depletion.
2
Analyze Statement III in relation to Statements I and II.
Statement III describes river flooding from upstream rainfall. This is a natural meteorological occurrence independent of local farm irrigation rules.
Extremely localized agricultural water regulations cannot cause macro-level weather occurrences like upstream rainfall.
3
Evaluate the option choices based on these logical relationships.
The evaluations identifying Statement I as the cause of Statement II, and Statement III as an independent event, are validated as correct.
Only options maintaining correct temporal sequence and plausible physical causality hold true.

Key Concept

Cause and Effect Analysis (Direct Causal Relationship vs. Independent Parallel Events)
Question 508Question

A municipal corporation is distributing its annual infrastructure development fund. Exactly 0.50.\overline{5} of the total fund is allocated to urban housing projects. From the remaining fund, 37\frac{3}{7} is assigned to public transportation. The rest of the fund is distributed equally between two sectors: renewable energy and public parks. If the amount allocated to renewable energy is $3.2\$3.2 million, what is the total annual infrastructure development fund?

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Answer: $25.2\$25.2 million

Answer

$25.2\$25.2 million
The correct sequence evaluates the recurring decimal 0.50.\overline{5} as 59\frac{5}{9}. This leaves 49\frac{4}{9} of the fund. Transport takes 37\frac{3}{7} of this remainder, which is 1263\frac{12}{63}. The new remainder is 491263=1663\frac{4}{9} - \frac{12}{63} = \frac{16}{63}. This is split equally, meaning renewable energy gets 863\frac{8}{63} of the total. Solving 863x=3.2\frac{8}{63}x = 3.2 gives x=25.2x = 25.2.

Step-by-Step Solution

1
Convert the recurring decimal to a fraction.
0.5=590.\overline{5} = \frac{5}{9}
Fractional form is required to perform precise subsequent operations without rounding errors.
2
Calculate the remaining fraction of the fund after the housing allocation.
159=491 - \frac{5}{9} = \frac{4}{9}
The next allocation is taken from the remaining fund, not the total fund.
3
Determine the fraction of the total fund allocated to public transportation.
37×49=1263=421\frac{3}{7} \times \frac{4}{9} = \frac{12}{63} = \frac{4}{21}
Multiplying the proportion (37\frac{3}{7}) by the available remainder (49\frac{4}{9}) yields its share of the total.
4
Calculate the new remaining fund for the last two sectors.
49421=28631263=1663\frac{4}{9} - \frac{4}{21} = \frac{28}{63} - \frac{12}{63} = \frac{16}{63}
Subtracting the transportation allocation from the previous remainder gives the final undistributed portion.
5
Determine the fraction of the total fund allocated to renewable energy.
12×1663=863\frac{1}{2} \times \frac{16}{63} = \frac{8}{63}
The problem states the final remainder is split equally between two sectors.
6
Equate the fraction to the given monetary value and solve for the total fund (xx).
863x=3.2    x=3.2×638=0.4×63=25.2\frac{8}{63}x = 3.2 \implies x = 3.2 \times \frac{63}{8} = 0.4 \times 63 = 25.2
This establishes the algebraic relationship to find the initial total.

Key Concept

Successive Fractional Operations and Recurring Decimals

Alternative Method

Instead of calculating absolute remaining fractions through subtraction at each step, you can chain the remaining proportions through direct multiplication: Total × (1 - 5/9) × (1 - 3/7) × (1/2) = Total × (4/9) × (4/7) × (1/2) = Total × (8/63). Setting (8/63) equal to 3.2 million quickly yields 25.2 million.
Estimated Time:2m 30s
Question 509Question

A student is reviewing fundamental number properties and evaluating several arithmetic scenarios. Identify which of the following assertions regarding number classification are mathematically valid. (Select all that apply)

Select all that apply

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Answer: The product of any non-zero rational number and an irrational number is always an irrational number.; Every non-terminating, recurring decimal expansion can be expressed as a rational number.

Answer

The mathematically valid assertions are that the product of a non-zero rational and an irrational number is always irrational, and that every non-terminating, recurring decimal is a rational number.
The assertions stating that the product of a non-zero rational and an irrational number is irrational, and that recurring decimals are rational, are fundamental and mathematically sound properties of the real number system.

Step-by-Step Solution

1
Evaluate the first assertion regarding the product of rational and irrational numbers.
The statement is determined to be valid.
Multiplying a ratio of integers (non-zero) by a non-repeating decimal inherently yields a non-repeating decimal.
2
Evaluate the arithmetic expression in the second assertion.
The expression equals 1717, which is a prime number.
Following order of operations, multiplication precedes addition (3×5=153 \times 5 = 15, then 15+2=1715 + 2 = 17).
3
Determine the unit digit for the third assertion.
The unit digit is 66, which is not a perfect square.
Because 4040 is a multiple of 44 (the cyclicity of base 22), the unit digit corresponds to the 44 th power in the cycle (24=162^4 = 16).
4
Evaluate the fourth assertion regarding recurring decimals.
The statement is determined to be valid.
All repeating decimals can be mathematically converted into a fraction format (e.g., 0.333...0.333... becomes 1/31/3), satisfying the definition of a rational number.

Key Concept

Classification of Rational and Irrational Numbers
Question 510Question

An inventory analyst is auditing two specific electronic components in a warehouse. He calculates that the product of their exact unit quantities is 32,17532,175, and the Highest Common Factor (HCF) of these two quantities is 1515. If there are more than 100100 units of each component currently in stock, what is the total combined quantity of both components?

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Answer: 360

Answer

The correct total combined quantity is 360 units.
By representing the numbers as 15x15x and 15y15y, we determine that 15x×15y=32,17515x \times 15y = 32,175, which simplifies to xy=143xy = 143. Factoring 143143 into co-prime pairs gives (1,143)(1, 143) and (11,13)(11, 13). Multiplying these by the HCF (1515) gives potential quantities of (15,2145)(15, 2145) and (165,195)(165, 195). Only the pair (165,195)(165, 195) satisfies the condition that both quantities must be greater than 100100. Their sum is 165+195=360165 + 195 = 360.

Step-by-Step Solution

1
Express the two unknown quantities mathematically using their HCF.
Let the quantities be 15x15x and 15y15y, where xx and yy are co-prime integers.
Since the HCF of the two numbers is 1515, both numbers must be multiples of 1515. Their remaining factors (xx and yy) cannot share any common factors other than 11.
2
Formulate an equation using the given product of the quantities.
15x×15y=32,17515x \times 15y = 32,175
The problem states the product of the two component quantities is equal to 32,17532,175.
3
Solve the equation for the product of the co-prime variables xx and yy.
225xy=32,175xy=32,175225=143225xy = 32,175 \Rightarrow xy = \frac{32,175}{225} = 143
Isolating xyxy simplifies the problem to finding two co-prime factors that multiply to 143143.
4
Identify all co-prime factor pairs of 143143.
The co-prime pairs are (1,143)(1, 143) and (11,13)(11, 13).
We must list all integer pairs that multiply to 143143 and verify they share no common divisors.
5
Calculate the possible original quantities and apply the boundary constraints.
Pair 1 gives (15,2145)(15, 2145). Pair 2 gives (165,195)(165, 195). Because the problem states both quantities are >100>100, we must choose (165,195)(165, 195).
The constraint strictly eliminates the first pair, as 1515 is not greater than 100100.
6
Sum the valid quantities.
165+195=360165 + 195 = 360
The question asks for the total combined quantity of both components.

Key Concept

The relationship between the Highest Common Factor (HCF) and the product of two numbers, utilizing co-prime factor pairs.
Question 511Question

Five executives—Ford, Greta, Harry, Ian, and Julia—are seated in a single straight row facing South during a board meeting.

Based on the following conditions, arrange the executives in the exact order they are seated from West to East (i.e., from the viewer's left to right):

1. Ford sits at the extreme left end of the row.
2. Julia sits immediately to the right of Ford.
3. Greta sits second to the right of Ian.
4. Harry sits adjacent to Ian, but does not sit next to Julia.

Drag items to arrange them in the correct order

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Answer

The correct seating order from West to East (viewer's left to right) is Greta, Harry, Ian, Julia, and Ford.
By accounting for the South-facing orientation, we reverse the standard left and right. Ford at the 'extreme left' places him on the viewer's far right (East). Following the relative positioning places Julia beside him, Ian in the middle, Harry at position 2, and Greta at position 1 (West).

Step-by-Step Solution

1
Determine the layout based on the facing direction.
Create five seats from West (viewer's left) to East (viewer's right). Since they face South, an executive's 'left' corresponds to East and their 'right' corresponds to West.
Crucial for correctly interpreting spatial clues without reversing the arrangement.
2
Place Ford and Julia using clues 1 and 2.
Ford is placed at position 5 (East/extreme left). Julia is placed at position 4 (immediate right of Ford).
Ford is at the extreme left (which is East when facing South). Julia is to his immediate right (which is West).
3
Place Ian and Greta using clue 3.
Ian is placed at position 3 and Greta is placed at position 1.
Greta is second to the right of Ian. The only remaining spaces with a gap of one seat are positions 1 and 3 (right = West).
4
Place Harry using clue 4.
Harry is placed at position 2.
Harry must be adjacent to Ian (position 3), which means he must be at position 2 or 4. Position 4 is occupied by Julia, so Harry takes position 2. This perfectly satisfies the condition that he is not next to Julia.

Key Concept

Linear Seating Arrangement with South-Facing Orientation
Question 512Question

A mathematician is formally classifying a set of numbers and analyzing their properties. Evaluate the mathematical validity of the following three propositions:

I. The number 00 is an even integer, but it is considered neither positive nor negative.
II. The fraction 227\frac{22}{7} is an irrational number because it is commonly used to represent the constant π\pi.
III. The absolute difference between any two distinct odd prime numbers is always an even composite number.

Which of the propositions given above is/are mathematically correct?

Show answer & explanation

Answer: Only Proposition I

Answer

Only Proposition I is mathematically correct.
Proposition I is correct because 0 is an integer that is divisible by 2 (making it even) and is strictly the neutral boundary between positive and negative values. Proposition II is incorrect because 22/7 is expressed as a ratio of two integers, making it a rational number, despite being used as an approximation for pi. Proposition III is incorrect because the difference between the odd prime numbers 5 and 3 is exactly 2, which is an even prime number rather than a composite number.

Step-by-Step Solution

1
Evaluate Proposition I regarding the properties of the number 0.
The number 0 is an integer, is divisible by 2 without a remainder (making it even), and serves as the boundary between positive and negative numbers. Therefore, Proposition I is true.
To verify the fundamental classification and parity of zero.
2
Evaluate Proposition II regarding the classification of the fraction 22/7.
The value 22/7 is a ratio of two integers (22 and 7). Any number that can be expressed as a fraction of integers with a non-zero denominator is a rational number. Therefore, Proposition II is false.
To distinguish between a rational fraction and the actual irrational constant (pi) it often approximates.
3
Evaluate Proposition III regarding the absolute difference between distinct odd prime numbers.
Consider the distinct odd prime numbers 5 and 3. Their absolute difference is |5 - 3| = 2. Since 2 is a prime number, the difference is not always an even composite number. Therefore, Proposition III is false.
To test the universal claim with a basic mathematical counterexample.

Key Concept

Classification of Rational vs. Irrational Numbers, Prime Numbers, and Properties of Zero
Question 513Question

A digital signal processing unit transmits three distinct telemetry data packets in continuous periodic cycles. The transmission cycles for the three packets take 1415\frac{14}{15} seconds, 75\frac{7}{5} seconds, and 6320\frac{63}{20} seconds, respectively. If all three packets are transmitted simultaneously at the beginning of a diagnostic test, after how many seconds will all three packets be transmitted together again for the first time?

Show answer & explanation

Answer: 1265\frac{126}{5}

Answer

1265\frac{126}{5}
To determine when all packets will transmit simultaneously again, we calculate the Least Common Multiple (LCM) of their cycle periods. The LCM of fractions is defined as the LCM of their numerators divided by the HCF of their denominators. Given the numerators (14, 7, 63) and denominators (15, 5, 20), we find LCM(14, 7, 63) = 126 and HCF(15, 5, 20) = 5. Dividing these yields the exact time of 1265\frac{126}{5} seconds.

Step-by-Step Solution

1
Identify the mathematical operation required.
The problem asks for the next simultaneous transmission of periodic cycles, which requires finding the Least Common Multiple (LCM) of the given time intervals: 1415\frac{14}{15}, 75\frac{7}{5}, and 6320\frac{63}{20}.
Repeating simultaneous events align at time intervals that are common multiples of their individual periods. The first alignment corresponds to the least common multiple.
2
Apply the rule for finding the LCM of fractions.
The correct mathematical formula is LCM=LCM of numeratorsHCF of denominators\text{LCM} = \frac{\text{LCM of numerators}}{\text{HCF of denominators}}.
This is the required procedure for finding the LCM of rational numbers expressed as simplified fractions.
3
Determine the LCM of the numerators.
The numerators are 1414, 77, and 6363. Their prime factorizations are 14=2×714 = 2 \times 7, 7=77 = 7, and 63=32×763 = 3^2 \times 7. Thus, LCM(14,7,63)=2×32×7=126\text{LCM}(14, 7, 63) = 2 \times 3^2 \times 7 = 126.
The LCM must consist of the highest power of all prime factors present among the numerators.
4
Determine the HCF of the denominators.
The denominators are 1515, 55, and 2020. Their prime factorizations are 15=3×515 = 3 \times 5, 5=55 = 5, and 20=22×520 = 2^2 \times 5. The Highest Common Factor(15,5,20)=5\text{Highest Common Factor}(15, 5, 20) = 5.
The HCF is the largest prime factor shared by all the denominators.
5
Calculate the final LCM of the transmission cycles.
Divide the LCM of the numerators by the HCF of the denominators to obtain exactly 1265\frac{126}{5} seconds.
Applying the values derived in the previous steps to the fraction formula yields the exact coincidence time.

Key Concept

Calculating the LCM of fractions to synchronize periodic events.
Question 514Question

During a system stress test, four data processing modules record their average latency per transaction (in seconds) as given below. Arrange the modules in ascending order based on their latency times (from fastest to slowest).

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Answer

The correct ascending sequence from fastest to slowest latency is Module Y, followed by Module X, then Module W, and finally Module Z.
By converting all latency values into extended decimals, we find Module Y (0.25656...0.25656...) is the smallest, followed by Module X (0.25714...0.25714...), then Module W (0.25757...0.25757...), and finally Module Z (0.25777...0.25777...). Therefore, the correct ascending order is Module Y, Module X, Module W, Module Z.

Step-by-Step Solution

1
Calculate the exact value for Module W using the HCF of fractions formula.
HCF = HCF(34,85)LCM(33,22)=1766\frac{\text{HCF}(34, 85)}{\text{LCM}(33, 22)} = \frac{17}{66}. Converted to a decimal, this is 0.25757...0.25757... (0.2570.2\overline{57}).
To standardize the mathematical expression into a comparable decimal format.
2
Convert the value for Module X into a decimal.
9350.2571428...\frac{9}{35} \approx 0.2571428...
Decimals allow for direct digit-by-digit comparison.
3
Expand the recurring decimal for Module Y to several decimal places.
0.256=0.2565656...0.2\overline{56} = 0.2565656...
To provide enough precision to compare digits past the third decimal place.
4
Convert the recurring decimal in Module Z to a fraction, multiply, and convert back to a decimal.
1.28=1281290=11690=58451.2\overline{8} = \frac{128-12}{90} = \frac{116}{90} = \frac{58}{45}. Then, 5845×15=58225\frac{58}{45} \times \frac{1}{5} = \frac{58}{225}. Converting to decimal gives 0.25777...0.25777... (0.2570.25\overline{7}).
To determine its exact decimal value for accurate comparison against the other modules.
5
Compare the decimal values digit by digit from left to right to establish the ascending order.
0.25656...0.25656... (Y) < 0.25714...0.25714... (X) < 0.25757...0.25757... (W) < 0.25777...0.25777... (Z).
The question asks for the fastest to slowest modules, which corresponds to the shortest to longest latency times (ascending numerical order).

Key Concept

Advanced comparison of fractions, recurring decimals, and the application of HCF/LCM rules for fractions.

Alternative Method

Find a common denominator for all fractions: 66 for W (17/66), 35 for X (9/35), 990 for Y (254/990), and 225 for Z (58/225). The LCM of 66, 35, 990, and 225 is 34650. Convert all fractions to this denominator to compare the exact numerators, though decimal conversion to the fourth digit is faster.
Estimated Time:2m 30s
Question 515Question

Consider all positive two-digit integers where the sum of their digits is exactly 1010. How many of these integers are prime numbers?

Show answer & explanation

Answer: 3

Answer

3
By listing all two-digit numbers with a digit sum of 10 (19, 28, 37, 46, 55, 64, 73, 82, 91) and testing them for primality, we find that only 19, 37, and 73 are prime. The number 91 is composite (7×137 \times 13), resulting in exactly 3 prime numbers meeting the condition.

Step-by-Step Solution

1
Identify all two-digit positive integers whose digits sum to 10.
The numbers are 19, 28, 37, 46, 55, 64, 73, 82, and 91.
Systematically listing the pairs of digits (from 1 to 9) that add up to 10 ensures no valid numbers are missed.
2
Evaluate each number to determine if it is prime or composite.
Even numbers (28, 46, 64, 82) and multiples of 5 (55) are composite. The remaining odd numbers to check are 19, 37, 73, and 91.
Applying basic divisibility rules for 2 and 5 quickly eliminates obvious composite numbers.
3
Test the remaining odd numbers for primality.
19, 37, and 73 are prime numbers. 91 is a composite number because 91=7×1391 = 7 \times 13.
A prime number has exactly two distinct positive divisors: 1 and itself. 91 is a common trap as its divisibility by 7 is not always immediately obvious.
4
Count the total number of prime numbers identified.
There are exactly 3 prime numbers in the set: 19, 37, and 73.
This directly answers the specific question asked in the stem.

Key Concept

Identification of Prime and Composite Numbers
Question 516Question

Six city planners—David, Elena, Felix, Grace, Hassan, and Iris—are sitting around a circular table for a development meeting. Some planners are facing the center of the table while others are facing outward.

Based on the following conditions, determine their exact seating arrangement:
1. David and Grace sit opposite each other, and both are facing the center.
2. Elena sits to the immediate left of David.
3. Iris sits second to the left of Elena.
4. Felix sits to the immediate right of Grace.
5. Elena, Hassan, and Iris all face the same direction.
6. Felix faces the opposite direction to Hassan.

Based on the seating arrangement, who sits to the immediate left of Hassan?

Show answer & explanation

Answer: Grace

Answer

Grace sits to the immediate left of Hassan.
Based on the clues, Hassan sits between Grace and Iris, facing outward. When facing outward, a person's left side corresponds to the counter-clockwise direction along the circle. The person seated immediately counter-clockwise to Hassan is Grace.

Step-by-Step Solution

1
Place David and Grace on a 6-position circular diagram.
David is at position 1 and Grace is at position 4. Both face the center.
Clue 1 states they sit opposite each other and both face the center.
2
Determine Elena's position and facing direction.
Elena is at position 2 and faces outward.
Clue 2 says Elena is to the immediate left of David. Since David faces the center, his left is clockwise, placing Elena at position 2. Clue 3 states Iris is second to Elena's left. If Elena faced the center, her second left would be position 4 (occupied by Grace). Thus, Elena must face outward.
3
Determine Iris's position.
Iris sits at position 6.
Since Elena is at position 2 and faces outward, 'left' means moving counter-clockwise. Two positions counter-clockwise from position 2 is position 6.
4
Place Felix and the remaining person, Hassan.
Felix is at position 3, and Hassan is at position 5.
Clue 4 states Felix is to the immediate right of Grace. Grace faces the center, so her right is counter-clockwise, which is position 3. Hassan must take the only remaining seat at position 5.
5
Determine the facing directions for Hassan, Iris, and Felix.
Hassan and Iris face outward. Felix faces the center.
Clue 5 states Elena, Hassan, and Iris face the same direction. Since Elena faces outward, Hassan and Iris also face outward. Clue 6 states Felix faces opposite to Hassan, so Felix faces the center.
6
Find the person to the immediate left of Hassan.
Grace
Hassan is at position 5 facing outward. For an outward-facing person, 'left' is counter-clockwise. The seat counter-clockwise from position 5 is position 4, which is occupied by Grace.

Key Concept

Mixed-facing circular seating arrangements and relative directional positioning based on orientation.
Question 517Question

Under the governance and rural transformation framework of the Government of India, the SVAMITVA (Survey of Villages and Mapping with Improvised Technology in Village Areas) scheme was rolled out nationwide to reform land record management. Which of the following statements accurately characterizes the primary mandate and operational mechanism of this scheme?

Show answer & explanation

Answer: It is a Central Sector Scheme under the Ministry of Panchayati Raj that deploys drone surveying technology to map inhabited rural areas and issue digitized property ownership cards.

Answer

It is a Central Sector Scheme under the Ministry of Panchayati Raj that deploys drone surveying technology to map inhabited rural areas and issue digitized property ownership cards.
The SVAMITVA (Survey of Villages and Mapping with Improvised Technology in Village Areas) scheme is a flagship Central Sector Scheme launched by the Ministry of Panchayati Raj. Implemented with the technical support of the Survey of India, State Revenue Departments, and State Panchayati Raj Departments, it uses drone mapping and high-precision Continuously Operating Reference Stations (CORS) networks to survey inhabited rural settlements (Abadi areas). This enables the generation of accurate spatial maps and the distribution of formal Property Cards (or Sampatti Patrak) to rural households, facilitating access to institutional credit and minimizing title litigation.

Step-by-Step Solution

1
Identify the nodal ministry and scheme classification of the SVAMITVA initiative.
The SVAMITVA scheme is a 100% centrally funded Central Sector Scheme administered by the Union Ministry of Panchayati Raj (MoPR).
Governance schemes in State PSC exams require accurate distinction between Central Sector and Centrally Sponsored schemes, as well as precise attribution of the administrative ministry.
2
Examine the technical methodology and geographic target area of the initiative.
The scheme utilizes drone-based aerial survey technology alongside the Survey of India to map inhabited village areas ('Abadi' parcels).
The core innovation of the scheme is replacing manual surveys with drone photogrammetry specifically in inhabited rural tracts rather than agricultural farmlands.
3
Evaluate the ultimate policy deliverable and socio-economic outcome.
The initiative creates definitive spatial property records and issues digitized 'Property Cards' (Sampatti Patrak) to rural property owners to enable financial monetization and reduce land disputes.
Establishing clear property rights serves as the foundational objective of the governance intervention.

Key Concept

SVAMITVA Scheme Architecture and Governance Mandate
Estimated Time:1m 15s
Question 518Question

A heated verbal altercation has erupted at a major construction site between field officers of the Public Works Department (PWD) and the Forest Department over the clearing of marked trees, bringing a sanctioned highway expansion to a complete halt. When a senior administrative mediator arrives to manage this escalating inter-departmental crisis, arrange the following actions in the most appropriate sequential order to assertively de-escalate and resolve the conflict.

Drag items to arrange them in the correct order

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Answer

The correct sequence is to first separate the hostile parties, then establish strict dialogue rules, listen uninterruptedly to both sides, identify mutual parameters, and finally draft an interim working protocol.
Effective conflict resolution in public administration requires a structured, phased approach. The sequence must logically move from immediate crisis management (separating the officers) to establishing administrative control (setting ground rules), followed by objective fact-finding (listening to constraints), synthesis (finding common ground), and finally, formal action (drafting an interim protocol). This matches established assertive leadership and mediation frameworks.

Step-by-Step Solution

1
De-escalate the immediate crisis.
Hostilities cease and emotional tension is lowered.
Rational negotiation cannot occur while parties are highly agitated or actively arguing.
2
Establish control and gather information.
A structured understanding of the regulatory conflict is achieved.
Assertively framing the discussion and actively listening ensures all technical constraints are known without triggering defensiveness.
3
Synthesize a collaborative solution.
An actionable, legally compliant interim protocol is created.
Aligning shared goals allows for temporary project continuity while a formal committee reviews the dispute.

Key Concept

Assertive De-escalation and Collaborative Conflict Resolution
Question 519Question

Carefully review the categorical statements and the corresponding conclusion below.

Statements:
- All high-frequency trading algorithms are automated financial systems.
- Some automated financial systems are unregulated market tools.

Conclusion:
Consequently, some high-frequency trading algorithms are unregulated market tools.

Determine whether it is true or false that this conclusion is a logically valid deduction from the given statements.

Show answer & explanation

Answer: False

Answer

False
The logical deduction is invalid due to the fallacy of the undistributed middle. The middle term ('automated financial systems') is the predicate of a universal affirmative statement and the subject of a particular affirmative statement, meaning it is undistributed in both instances. Without a distributed middle term, there is no structural guarantee linking the other two terms.

Step-by-Step Solution

1
Identify the categorical relationship established in the first statement.
The statement 'All high-frequency trading algorithms are automated financial systems' means the entire set of these algorithms is enclosed within a larger, broader set of automated systems.
Understanding subset-superset boundaries is critical to prevent assuming two categories are perfectly identical.
2
Analyze the relationship introduced in the second statement.
The statement 'Some automated financial systems are unregulated market tools' establishes a partial overlap between automated systems and unregulated tools.
This determines how the third term relates to the common middle term.
3
Evaluate whether the conclusion is an absolute necessity.
Because the algorithms are just one part of the automated systems, the overlap with unregulated tools might happen in a completely different part of the automated systems category. Therefore, we cannot definitively conclude that they intersect.
In formal syllogisms, a valid conclusion must hold true under all possible configurations of the premises.

Key Concept

Distribution of Terms and Invalid Conversion in Syllogisms
Question 520Question

Match the flagship state government welfare schemes in List-I with their corresponding primary policy objectives and target sectors in List-II:

Click a left item, then click its matching right item

Items

Indira Gandhi Shehri Rozgar Guarantee Yojana (Rajasthan)
Mukhyamantri Bal Ashirwad Yojana (Madhya Pradesh)
Rythu Bandhu Scheme (Telangana)
Mukhyamantri Vridhjan Pension Yojana (Bihar)

Matches

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Answer

Indira Gandhi Shehri Rozgar Guarantee Yojana matches with guaranteed urban wage employment; Mukhyamantri Bal Ashirwad Yojana matches with financial and educational support for institutional orphans; Rythu Bandhu Scheme matches with direct agricultural input investment support per acre; and Mukhyamantri Vridhjan Pension Yojana matches with universal monthly social security pension for senior citizens aged 60 and above.
Each scheme is accurately mapped to its core sector: Rajasthan's Indira Gandhi Shehri Rozgar Guarantee Yojana provides urban livelihood security through guaranteed manual and skilled wage work; Madhya Pradesh's Mukhyamantri Bal Ashirwad Yojana targets aftercare welfare for young adults leaving childcare institutions; Telangana's Rythu Bandhu delivers direct farmer investment assistance per acre per season; and Bihar's Mukhyamantri Vridhjan Pension Yojana provides universal social security to senior citizens aged 60 and above.

Step-by-Step Solution

1
Analyze the mandate of Rajasthan's urban welfare policy
Identify Indira Gandhi Shehri Rozgar Guarantee Yojana as the urban counterpart to rural employment guarantees, providing 125 days of wage work to urban families.
Urban employment schemes focus on creating urban community assets and providing livelihood security in municipal areas.
2
Evaluate Madhya Pradesh's child rehabilitation and aftercare welfare policy
Identify Mukhyamantri Bal Ashirwad Yojana as the aftercare financial aid and skill rehabilitation program for orphan youths leaving child care homes at age 18.
Child welfare policies provide transitional security from foster/institutional care to independent adult living.
3
Examine Telangana's agrarian welfare architecture
Identify Rythu Bandhu as the direct benefit transfer mechanism providing crop investment aid per acre per crop season.
Agricultural investment policies aim to free small and marginal farmers from informal debt traps.
4
Review Bihar's social safety net for elderly citizens
Identify Mukhyamantri Vridhjan Pension Yojana as a universal non-contributory pension scheme for individuals aged 60 and above.
Universal old-age pension schemes eliminate strict BPL category exclusions to provide dignified elderly support.

Key Concept

State Government Schemes and Welfare Policies
Estimated Time:1m 15s
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