Number Theory and Operations

159 soru

Soru 41Soru →

A logistics convoy is transporting supplies to a remote base. On the first day of the trip, they complete 30%30\% of the total distance. On the second day, they complete 40%40\% of the remaining distance. If they still have 210210 miles left to travel, what is the total distance of the trip in miles?

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Cevap: 500

Cevap

The total distance of the trip is 500 miles.
The correct answer accurately accounts for the successive percentages by applying the second day's percentage to the remaining distance. After traveling 30% of the trip, 70% remains. Leaving 40% of this remaining 70% completed means 60% of the 70% is left uncompleted, which equals 42% of the total distance. Setting 42% equal to the 210 remaining miles gives a total distance of 500 miles.

Adım Adım Çözüm

1
Determine the percentage of the trip remaining after the first day.
100%−30%=70%100\% - 30\% = 70\%
The second day's travel is based on the remaining distance, not the total distance.
2
Calculate the percentage of the remaining distance that is left after the second day.
100%−40%=60%100\% - 40\% = 60\%
Since they completed 40% of the remaining distance, 60% of that remaining distance is still uncompleted.
3
Calculate the percentage of the total distance that the final remaining 210 miles represents.
0.70×0.60=0.420.70 \times 0.60 = 0.42, which is 42%42\% of the total distance.
Successive percentages are applied by multiplying the decimal forms of the remaining portions.
4
Set up an equation to solve for the total distance, D.
0.42D=210  ⟹  D=210÷0.42=5000.42D = 210 \implies D = 210 \div 0.42 = 500
Dividing the remaining miles by the remaining percentage of the total trip yields the original total distance.

Anahtar Kavram

Calculating successive percentage changes by adjusting the base for each subsequent calculation.
Soru 42Soru →

Evaluate each of the following arithmetic expressions. Then, arrange the expressions in order from the smallest resulting value to the largest resulting value.

Öğeleri doğru sıraya koymak için sürükleyin

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Cevap

The correct sequence from smallest to largest is: 10−2×(4−1)210 - 2 \times (4 - 1)^2, 10−(2×4)−1210 - (2 \times 4) - 1^2, 10−2×4−(−1)310 - 2 \times 4 - (-1)^3, and (10−2)×4−12(10 - 2) \times 4 - 1^2.
Evaluating each expression using the correct order of operations yields -8, 31, 1, and 3 respectively. Arranging these integer values from smallest to largest dictates the correct order.

Adım Adım Çözüm

1
Evaluate the first expression: 10−2×(4−1)210 - 2 \times (4 - 1)^2
−8-8
Applying PEMDAS: solve inside parentheses (3)(3), apply the exponent (32=9)(3^2 = 9), multiply (2×9=18)(2 \times 9 = 18), and subtract (10−18=−8)(10 - 18 = -8).
2
Evaluate the second expression: (10−2)×4−12(10 - 2) \times 4 - 1^2
3131
Applying PEMDAS: solve inside parentheses (8)(8), apply the exponent (12=1)(1^2 = 1), multiply (8×4=32)(8 \times 4 = 32), and subtract (32−1=31)(32 - 1 = 31).
3
Evaluate the third expression: 10−(2×4)−1210 - (2 \times 4) - 1^2
11
Applying PEMDAS: multiply inside parentheses (8)(8), apply the exponent (12=1)(1^2 = 1), and subtract from left to right (10−8=2;2−1=1)(10 - 8 = 2; 2 - 1 = 1).
4
Evaluate the fourth expression: 10−2×4−(−1)310 - 2 \times 4 - (-1)^3
33
Applying PEMDAS: apply the exponent ((−1)3=−1)((-1)^3 = -1), multiply (2×4=8)(2 \times 4 = 8), and subtract from left to right (10−8=2;2−(−1)=3)(10 - 8 = 2; 2 - (-1) = 3).
5
Arrange the evaluated numbers from smallest to largest
−8<1<3<31-8 < 1 < 3 < 31
Comparing the integer values yields the final logical order of the respective expressions.

Anahtar Kavram

Evaluating arithmetic expressions sequentially by applying the correct order of operations (PEMDAS) and then sorting the numerical values.
Soru 43Soru →

A naval fleet has a certain number of vessels. Currently, 20%20\% of the fleet is undergoing long-term maintenance. Of the operational vessels remaining, 25%25\% are currently deployed on active missions. If there are exactly 3333 operational vessels remaining at the home port, what is the total number of vessels in the entire fleet?

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Cevap: 5555

Cevap

The total number of vessels in the entire fleet is 5555.
The correct answer is found by tracking the remaining percentages step-by-step. Since 20% of the fleet is in maintenance, 80% remains operational. The 25% deployment rate applies to this 80%, meaning 20% of the total fleet is deployed (0.25 * 0.80 = 0.20). Subtracting the deployed vessels leaves 60% of the original fleet at the port. Finally, dividing the 33 vessels by 0.60 yields the original total fleet size of 55.

Adım Adım Çözüm

1
Determine the percentage of the fleet that is not in maintenance.
100%−20%=80%100\% - 20\% = 80\%
The 25%25\% deployment rate applies only to the remaining operational vessels.
2
Calculate the percentage of the total fleet that is deployed.
25%25\% of 80%=0.25×80%=20%80\% = 0.25 \times 80\% = 20\%
To find the deployed amount relative to the whole fleet, multiply the successive percentages.
3
Determine the percentage of the total fleet that remains at the home port.
80%−20%=60%80\% - 20\% = 60\%
Subtracting the deployed vessels from the operational vessels gives the portion remaining at port.
4
Set up an equation and solve for the total number of vessels in the fleet (xx).
0.60x=33⇒x=330.60=550.60x = 33 \Rightarrow x = \frac{33}{0.60} = 55
The 60%60\% of the total fleet is equal to the 3333 vessels explicitly counted at the port.

Anahtar Kavram

Successive Percentage Calculations and Reversing Percentages
Soru 44Soru →

In a military motor pool, the ratio of trucks to jeeps is 2:32:3, and the ratio of jeeps to motorcycles is 4:54:5. If there are exactly 140140 vehicles among these three types, how many more motorcycles are there than trucks?

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Cevap: 28

Cevap

There are 28 more motorcycles than trucks.
To solve this, the two separate ratios must be unified. By finding the least common multiple for the overlapping term (jeeps, which are represented by 3 in the first ratio and 4 in the second), we scale the ratios to 8:12 and 12:15. This creates a combined ratio of 8:12:15 for trucks to jeeps to motorcycles. Adding these parts gives 35 total proportional units. Dividing the actual total (140 vehicles) by 35 units reveals that each unit equals 4 vehicles. The difference between motorcycles (15 units) and trucks (8 units) is 7 units. Multiplying 7 units by 4 vehicles per unit yields 28.

Adım Adım Çözüm

1
Identify the common entity between the two given ratios to create a single, unified ratio.
Jeeps are the common entity. Trucks : Jeeps = 2:32:3, and Jeeps : Motorcycles = 4:54:5.
You cannot compare trucks and motorcycles directly or find the total parts until all three vehicles share the same proportional scale.
2
Find the least common multiple (LCM) for the 'Jeeps' portion of both ratios and scale them.
The LCM of 33 and 44 is 1212. Multiply the first ratio by 44 to get 8:128:12. Multiply the second ratio by 33 to get 12:1512:15. The combined ratio of Trucks : Jeeps : Motorcycles is 8:12:158:12:15.
Scaling ensures the common term is equal in both ratios, allowing them to be combined safely.
3
Calculate the value of a single ratio part based on the total number of vehicles.
Total parts = 8+12+15=358 + 12 + 15 = 35. Divide the total vehicles by total parts: 140÷35=4140 \div 35 = 4 vehicles per part.
This establishes the multiplier needed to convert ratio units into actual vehicle counts.
4
Find the difference in parts between motorcycles and trucks, then multiply by the part value.
Motorcycles (1515 parts) minus trucks (88 parts) equals 77 parts. 7×4=287 \times 4 = 28 vehicles.
Subtracting the parts before multiplying by the scale factor is more efficient than finding the total of each vehicle first, though both methods yield 28.

Anahtar Kavram

Combining multiple distinct ratios using a least common multiple to form a unified proportional relationship.
Soru 45Soru →

Simplify the given mathematical expression. Which of the following represents its final value?

−5−3×(−2)+4 -5 - 3 \times (-2) + 4
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Cevap: 5

Cevap

5
According to the order of operations, multiplication must be evaluated before addition and subtraction. First, multiply 3 by -2 to get -6. Subtracting this negative product from -5 gives -5 - (-6), which correctly simplifies to -5 + 6 = 1. Finally, add 4 to reach the correct final answer of 5.

Adım Adım Çözüm

1
Identify the operations in the expression and determine their correct order of execution.
The expression contains subtraction, multiplication, and addition. Multiplication must be performed first.
According to the standard order of operations (PEMDAS), multiplication has a higher priority than addition and subtraction.
2
Perform the multiplication step.
3×(−2)=−63 \times (-2) = -6. The expression becomes −5−(−6)+4-5 - (-6) + 4.
Calculate the product before processing the outer subtraction.
3
Simplify the subtraction of a negative number.
−5−(−6)+4-5 - (-6) + 4 becomes −5+6+4-5 + 6 + 4.
Subtracting a negative integer is mathematically equivalent to adding its positive counterpart.
4
Evaluate the remaining addition and subtraction from left to right.
−5+6=1-5 + 6 = 1, and 1+4=51 + 4 = 5.
Addition and subtraction hold the same operational priority and are resolved sequentially from left to right.

Anahtar Kavram

Order of Operations with Signed Integers

Alternatif Yöntem

Instead of subtracting the product of 3 and -2, you can treat the subtraction symbol as a negative sign attached to the 3. This changes the multiplication step to (-3) * (-2) = 6. The entire expression then immediately becomes -5 + 6 + 4, which easily sums to 5.
Tahmini Süre:45s
Soru 46Soru →

A naval shipyard increases its dry dock maintenance workforce by 12.5%12.5\% to meet new project demands. If the current workforce size after the increase is 810810 personnel, what was the original size of the workforce before the increase?

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Cevap: 720

Cevap

720
The scenario requires a reverse percentage calculation. The final count of 810810 personnel represents the original workforce plus a 12.5%12.5\% increase, meaning 810810 is exactly 112.5%112.5\% (or 98\frac{9}{8}) of the original amount. To find the original amount, you set up the equation 98x=810\frac{9}{8}x = 810 and solve for xx by multiplying 810810 by the reciprocal 89\frac{8}{9}, which equals 720720.

Adım Adım Çözüm

1
Identify the relationship between the final amount and the initial amount.
A 12.5%12.5\% increase means the final amount is 100%+12.5%=112.5%100\% + 12.5\% = 112.5\% of the original amount.
To correctly set up an algebraic representation of the percentage growth based on the unknown starting value.
2
Convert the new percentage multiplier into a fraction.
Knowing that 12.5%=1812.5\% = \frac{1}{8}, the multiplier for a 12.5%12.5\% increase is 1+18=981 + \frac{1}{8} = \frac{9}{8}.
Using fractions makes mental arithmetic much simpler and faster without a calculator.
3
Set up the equation to solve for the original amount.
Letting xx represent the original workforce size, the equation is 98x=810\frac{9}{8}x = 810.
This translates the word problem into a solvable mathematical equation.
4
Solve the equation for xx.
x=810×89=90×8=720x = 810 \times \frac{8}{9} = 90 \times 8 = 720.
Isolating xx provides the initial workforce size before the increase.

Anahtar Kavram

Reverse percentage calculations and percentage-to-fraction conversions.
Tahmini Süre:1m 0s
Soru 47Soru →

If x=−3x = -3 and y=−5y = -5, what is the value of the following expression?

x2+2x×∣y∣−(x−y)x^2 + 2x \times |y| - (x - y)
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Cevap: -23

Cevap

The correct answer is -23.
By accurately applying the rules for negative integers, (-3)^2 evaluates to a positive 9. The absolute value |-5| evaluates to a positive 5. Following the order of operations, the multiplication 2(-3) * 5 is performed next, yielding -30. Finally, subtracting the evaluation of the parenthetical group (2) from the sum of 9 and -30 results in exactly -23.

Adım Adım Çözüm

1
Substitute the values of x and y into the expression.
(−3)2+2(−3)×∣−5∣−(−3−(−5))(-3)^2 + 2(-3) \times |-5| - (-3 - (-5))
Direct substitution is the first step in evaluating algebraic expressions.
2
Evaluate the terms inside parentheses and absolute value brackets.
∣−5∣=5|-5| = 5 and (−3−(−5))=(−3+5)=2(-3 - (-5)) = (-3 + 5) = 2. The expression becomes: (−3)2+2(−3)×5−2(-3)^2 + 2(-3) \times 5 - 2
According to the order of operations, grouping symbols like absolute value and parentheses must be resolved first.
3
Evaluate the exponent.
(−3)2=9(-3)^2 = 9. The expression becomes: 9+2(−3)×5−29 + 2(-3) \times 5 - 2
Exponents must be calculated before multiplication, addition, and subtraction. A negative number squared yields a positive result.
4
Perform the multiplication.
2(−3)×5=−6×5=−302(-3) \times 5 = -6 \times 5 = -30. The expression becomes: 9+(−30)−29 + (-30) - 2
Multiplication is performed before addition and subtraction.
5
Perform the remaining addition and subtraction from left to right.
9−30−2=−21−2=−239 - 30 - 2 = -21 - 2 = -23
Addition and subtraction are the final steps in the order of operations.

Anahtar Kavram

Evaluating expressions using properties of negative integers and absolute value
Tahmini Süre:1m 0s
Soru 48Soru →

A fuel tank at a military base is initially filled to 80%80\% of its total capacity. After a training exercise, the fuel level decreases by 35%35\% of its current volume. If 260260 gallons of fuel remain in the tank after the exercise, what is the total capacity of the fuel tank in gallons?

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Cevap: 500

Cevap

500
To find the total capacity, we must track the percentage of fuel at each stage relative to the total capacity. Initially, the tank holds 80%80\% of its capacity, or 0.800.80. A decrease of 35%35\% means 65%65\% of that fuel remains. Multiplying the initial proportion (0.800.80) by the remaining proportion (0.650.65) yields 0.520.52. This indicates that the final 260260 gallons represent exactly 52%52\% of the tank's total capacity. Setting up the equation 0.52C=2600.52C = 260 and dividing 260260 by 0.520.52 gives a total capacity of 500500 gallons.

Adım Adım Çözüm

1
Define a variable for the total capacity and express the initial fuel volume.
Initial volume = 0.80C0.80C
The tank is starting at 80%80\% of its total capacity (CC).
2
Determine the percentage of fuel remaining after the exercise.
Remaining percentage = 100%−35%=65%100\% - 35\% = 65\%
A 35%35\% decrease means that 65%65\% of the fuel that was in the tank before the exercise is still there.
3
Express the final remaining volume in terms of the total capacity (CC).
0.65×0.80C=0.52C0.65 \times 0.80C = 0.52C
Applying the 65%65\% remaining proportion to the initial 0.80C0.80C volume gives the final percentage of the total capacity.
4
Set up an equation using the known final volume and solve for CC.
0.52C=260⇒C=2600.52=5000.52C = 260 \Rightarrow C = \frac{260}{0.52} = 500
Equating the algebraic expression to the 260260 gallons given in the problem isolates the unknown base capacity.

Anahtar Kavram

Calculating successive percentages and identifying an unknown base value.
Soru 49Soru →

An aviation squadron reduces its weekly flight hours by 15%15\% to conserve fuel. If the new weekly flight schedule is 340340 hours, what was the original number of weekly flight hours before the reduction?

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Cevap: 400

Cevap

The original number of weekly flight hours was 400.
The problem describes a reverse percentage scenario. Because the hours were reduced by 15%, the current 340 hours represent 85% (100% - 15%) of the original schedule. To find the original amount, you divide the current amount by the decimal form of the remaining percentage: 340 / 0.85 = 400.

Adım Adım Çözüm

1
Determine what percentage the new hours represent compared to the original.
The new hours represent 100%−15%=85%100\% - 15\% = 85\% of the original hours.
A reduction of 15% means 85% of the original amount remains.
2
Set up an equation where the original hours are represented by the variable xx.
0.85x=3400.85x = 340
This translates the relationship into an algebraic equation to solve for the unknown original base.
3
Solve for xx by dividing both sides by 0.850.85.
x=3400.85=400x = \frac{340}{0.85} = 400
Isolating xx provides the original number of flight hours.

Anahtar Kavram

Reverse Percentage Calculations

Alternatif Yöntem

You can set this up as a proportion: 85100=340x\frac{85}{100} = \frac{340}{x}. Cross-multiply to get 85x=3400085x = 34000, and divide by 85 to find x=400x = 400.
Tahmini Süre:1m 0s
Soru 50Soru →

If x=−3x = -3, y=−5y = -5, and z=2z = 2, what is the value of the expression −2∣x2−∣y−3z∣∣+4x-2|x^2 - |y - 3z|| + 4x?

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Cevap: -16

Cevap

-16
The correct answer is found by strictly adhering to the order of operations and properties of absolute values. First, the inner absolute value |-5 - 3(2)| evaluates to |-11|, which is 11. The expression then simplifies to -2|(-3)² - 11| + 4(-3). Squaring -3 gives 9, so the expression inside the outer absolute value becomes 9 - 11, which is -2. The absolute value of -2 is 2. Multiplying this by the leading coefficient of -2 gives -4, and adding 4(-3), which is -12, results in -16.

Adım Adım Çözüm

1
Substitute the given variable values into the expression.
-2|(-3)² - |-5 - 3(2)|| + 4(-3)
To prepare the expression for evaluation by replacing variables with their known numeric values.
2
Evaluate the innermost operations following the order of operations, starting with the inner absolute value.
-5 - 3(2) = -5 - 6 = -11, so |-11| = 11
The order of operations (PEMDAS) requires evaluating multiplication before subtraction, and operations inside the innermost grouping symbols first.
3
Evaluate the exponent and substitute the result of the inner absolute value back into the expression.
-2|9 - 11| - 12
Exponents must be evaluated before subtraction within the remaining absolute value.
4
Evaluate the subtraction inside the remaining absolute value and apply the absolute value function.
|9 - 11| = |-2| = 2
The absolute value of any non-zero integer is its positive counterpart.
5
Multiply by the leading coefficient and add the final term.
-2(2) - 12 = -4 - 12 = -16
Multiplication must be performed before subtraction to find the final value.

Anahtar Kavram

Evaluating multi-step algebraic expressions with nested absolute values
Soru 51Soru →

Determine the exact value of the expression below by applying the correct sequence of mathematical operations:

20−2×(3−5)3+−164 20 - 2 \times (3 - 5)^3 + \frac{-16}{4}

Which of the following represents the correct numerical result?

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Cevap: 32

Cevap

32
Following the proper order of operations, we first simplify the parentheses to get -2. Next, we apply the exponent: (−2)3(-2)^3 equals -8. Then we perform multiplication and division: −2×−8-2 \times -8 gives a positive 16, and dividing -16 by 4 gives -4. Finally, substituting these values back into the expression leaves 20+16−420 + 16 - 4, which evaluates to 32.

Adım Adım Çözüm

1
Evaluate the expression inside the parentheses: (3−5)(3 - 5)
-2
According to the order of operations, operations inside parentheses must be resolved first.
2
Apply the exponent to the result of the parentheses: (−2)3(-2)^3
-8
Exponents must be evaluated before multiplication or division.
3
Perform the multiplication: −2×(−8)-2 \times (-8)
16
Multiplication is performed left-to-right before any addition or subtraction. Note that multiplying two negative numbers yields a positive result.
4
Perform the division: −164\frac{-16}{4}
-4
Division is also resolved before addition and subtraction. A negative divided by a positive yields a negative result.
5
Complete the final addition and subtraction left-to-right: 20+16−420 + 16 - 4
32
Once all higher-order operations are complete, add and subtract from left to right.

Anahtar Kavram

Order of Operations with Signed Numbers and Exponents
Soru 52Soru →

A tool kit originally costs $40\$40. Its price is increased to $50\$50. What is the percentage increase in the price of the tool kit?

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Cevap: 25%25\%

Cevap

25%25\%
The correct percentage increase is found by determining the difference between the new price and the old price ($10\$10), and then dividing that difference by the original price ($40\$40). The fraction 10/4010/40 reduces to 1/41/4, which equals 0.250.25 or 25%25\%.

Adım Adım Çözüm

1
Calculate the absolute increase in price.
$50−$40=$10\$50 - \$40 = \$10
The percentage increase is always based on the amount of change in value.
2
Divide the price increase by the original price to find the decimal rate.
10÷40=0.2510 \div 40 = 0.25
Percentage change must be calculated relative to the starting amount, not the final amount.
3
Convert the decimal rate to a percentage.
0.25×100=25%0.25 \times 100 = 25\%
Multiplying a decimal by 100 formats it as a standard percentage.

Anahtar Kavram

Percentage Increase
Tahmini Süre:45s
Soru 53Soru →

An aviation mechanic is preparing 6060 liters of a de-icing fluid mixture. The current mixture has a ratio of pure chemical to water of 3:23:2. To meet severe weather regulations, the mechanic must alter the mixture so that the ratio of pure chemical to water is 4:14:1. Assuming no water is removed, how many liters of pure chemical must be added to the current mixture?

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Cevap: 60

Cevap

60
The correct approach requires recognizing that the amount of water remains constant at 24 liters. To achieve a new ratio of 4 parts chemical to 1 part water, the final mixture must contain 4 times as much chemical as water (24×4=9624 \times 4 = 96 liters). Since there are already 36 liters of chemical in the mixture, you must add 96−36=6096 - 36 = 60 liters of pure chemical.

Adım Adım Çözüm

1
Determine the total number of parts in the initial ratio.
3+2=53 + 2 = 5 total parts.
To find the volume of a single part, you must first know how many total parts make up the 60-liter mixture.
2
Calculate the initial volume of pure chemical and water.
60÷5=1260 \div 5 = 12 liters per part. Pure chemical = 3×12=363 \times 12 = 36 liters. Water = 2×12=242 \times 12 = 24 liters.
Finding the absolute volumes allows you to establish the constant value (water) that will be used for the new proportion.
3
Set up a proportion for the new mixture using the constant water volume.
Let xx be the added chemical. The new ratio is 36+x24=41\frac{36 + x}{24} = \frac{4}{1}.
Since no water is removed, the water volume remains 24 liters. The new chemical amount must maintain a 4:1 relationship with this 24 liters.
4
Solve the proportion for xx.
36+x=24×4⇒36+x=96⇒x=6036 + x = 24 \times 4 \Rightarrow 36 + x = 96 \Rightarrow x = 60 liters.
Isolating xx provides the exact volume of pure chemical that needs to be added to reach the desired target ratio.

Anahtar Kavram

Multi-step proportion scaling with a constant part and a changing total.
Soru 54Soru →

Arrange the mathematical steps in the correct sequence to evaluate the following expression according to the standard order of operations (PEMDAS):

12−4×∣−5+23∣ 12 - 4 \times \left| -5 + 2^3 \right|

Öğeleri doğru sıraya koymak için sürükleyin

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Cevap

The correct sequence starts with evaluating the exponent inside the absolute value, followed by addition, resolving the absolute value, multiplication, and finally subtraction.
Following the standard order of operations (PEMDAS), operations inside grouping symbols are prioritized. The absolute value bars act as a grouping symbol. Inside, the exponent is evaluated first, then the addition. The absolute value is then applied to the result. Finally, outside the grouping symbol, multiplication takes precedence over subtraction.

Adım Adım Çözüm

1
Evaluate the exponent inside the absolute value.
12−4×∣−5+8∣ 12 - 4 \times \left| -5 + 8 \right|
Exponents within grouping symbols (absolute value) must be evaluated first.
2
Perform the addition inside the absolute value.
12−4×∣3∣ 12 - 4 \times \left| 3 \right|
Complete the operations inside the grouping symbols.
3
Resolve the absolute value.
12−4×3 12 - 4 \times 3
The absolute value of 33 is 33.
4
Perform the multiplication.
12−12 12 - 12
Multiplication precedes subtraction.
5
Perform the subtraction.
0 0
Subtraction is the final remaining operation.

Anahtar Kavram

Order of Operations (PEMDAS)
Soru 55Soru →

What is the value of the expression −3×∣−2∣−(−5)-3 \times |-2| - (-5)?

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Cevap: -1

Cevap

The correct answer is -1.
The expression must be solved by first finding the absolute value of −2-2, which is 22. Multiplying −3-3 by 22 gives −6-6. Finally, subtracting −5-5 from −6-6 is the exact same as adding 55 to −6-6, which results in −1-1.

Adım Adım Çözüm

1
Evaluate the absolute value expression.
∣−2∣=2|-2| = 2
Absolute value represents the distance of a number from zero, which is always non-negative.
2
Perform the multiplication.
−3×2=−6-3 \times 2 = -6
According to the order of operations (PEMDAS), multiplication must be completed before addition and subtraction. Multiplying a negative integer by a positive integer yields a negative integer.
3
Perform the subtraction.
−6−(−5)=−6+5=−1-6 - (-5) = -6 + 5 = -1
Subtracting a negative integer is mathematically equivalent to adding its positive counterpart.

Anahtar Kavram

Integer Sign Rules and Order of Operations
Soru 56Soru →

Read the scenario and fill in the blank with the correct numeric value.

Aşağıdaki boşlukları doldurun

A recruit is on a 1212-mile training march. If the recruit has completed 75%75\% of the total distance, they have marched miles.
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Cevap

9
To find 75%75\% of a 1212-mile march, convert the percentage into a decimal (0.750.75) or a simplified fraction (34\frac{3}{4}). Multiplying the total distance of 1212 miles by 34\frac{3}{4} yields 99 miles. Therefore, the recruit has completed 99 miles of the march.

Adım Adım Çözüm

1
Identify the total distance and the percentage of the distance completed.
The total distance is 1212 miles, and the percentage completed is 75%75\%.
To calculate the distance completed, the whole amount and the percentage rate must be identified.
2
Convert the percentage to a fraction or a decimal.
75%=75100=3475\% = \frac{75}{100} = \frac{3}{4}, or 0.750.75.
Percentages must be converted into standard numerical forms to perform arithmetic operations.
3
Multiply the total distance by the fraction or decimal.
12×34=912 \times \frac{3}{4} = 9, or 12×0.75=912 \times 0.75 = 9.
Finding a percentage of a number requires multiplying the total by the percentage rate.

Anahtar Kavram

Calculating a percentage of a whole number.
Soru 57Soru →

The product of two negative integers is always a positive integer.

Cevabı ve açıklamayı göster

Cevap: True

Cevap

True
The statement is correct because the mathematical rule for multiplying two integers with identical negative signs dictates that their product is positive.

Adım Adım Çözüm

1
Recall the rules for multiplying integers with the same sign.
A negative number multiplied by another negative number equals a positive number.
This is a fundamental property of integer multiplication.
2
Apply the rule to a concrete example to verify.
For instance, −3×−4=12-3 \times -4 = 12.
Using concrete integers confirms that the product is indeed a positive integer.

Anahtar Kavram

Sign Rules for Integer Operations
Tahmini Süre:15s
Soru 58Soru →

Complete the statements below with the correct numerical values.

Aşağıdaki boşlukları doldurun

An upgraded water purification system at a naval facility processes 5,2005,200 gallons of water per hour. This new processing rate represents a 30%30\% increase over the system's previous capacity.

The previous capacity of the system was
gallons per hour. The upgrade increased the processing capacity by gallons per hour.
Cevabı ve açıklamayı göster

Cevap

The previous capacity was 4,000 gallons per hour, and the upgrade increased the capacity by 1,200 gallons per hour.
A 30% increase means the new capacity is 130% of the original capacity. Dividing the new capacity (5,200) by 1.30 gives the original capacity of 4,000 gallons per hour. The numerical increase is the difference between the new and old capacities: 5,200 - 4,000 = 1,200 gallons per hour.

Adım Adım Çözüm

1
Set up an equation representing the percentage increase.
Let x be the previous capacity. Since there is a 30% increase, the new capacity is 100% + 30% = 130% of the previous capacity. Therefore, 1.3x = 5200.
To find the original base amount before a percentage increase, we must express the final amount as a percentage of the original.
2
Solve the equation for the previous capacity (x).
x = 5200 / 1.3 = 4000. This is the previous capacity.
Dividing the final amount by the percentage multiplier isolates the original base.
3
Calculate the amount of the capacity increase.
5200 - 4000 = 1200. This is the amount of the increase.
Subtracting the original capacity from the final capacity yields the exact volume added by the upgrade.

Anahtar Kavram

Reverse Percentage and Percentage Increase
Soru 59Soru →

Arrange the following mathematical values related to factors, multiples, and primes in ascending order (from least to greatest).

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct ascending sequence is: the total number of positive factors of 120 (16), followed by the sum of the distinct prime factors of 330 (21), followed by the GCF of 84 and 140 (28), and finally the LCM of 2, 3, 4, and 5 (60).
Evaluating each statement yields the numerical values 1616, 2121, 2828, and 6060. Arranging these from least to greatest gives the correct order: Factor count of 120120 (16), Prime sum of 330330 (21), GCF of 8484 and 140140 (28), and LCM of 2,3,4,2, 3, 4, and 55 (60).

Adım Adım Çözüm

1
Calculate the total number of positive factors of 120120.
1616
By finding the prime factorization (120=23×31×51120 = 2^3 \times 3^1 \times 5^1) and adding 11 to each exponent before multiplying them, we get (3+1)×(1+1)×(1+1)=4×2×2=16(3+1) \times (1+1) \times (1+1) = 4 \times 2 \times 2 = 16.
2
Calculate the sum of the distinct prime factors of 330330.
2121
The prime factorization is 330=33×10=3×11×2×5330 = 33 \times 10 = 3 \times 11 \times 2 \times 5. The distinct primes are 2,3,5,2, 3, 5, and 1111. Their sum is 2+3+5+11=212 + 3 + 5 + 11 = 21.
3
Determine the greatest common factor (GCF) of 8484 and 140140.
2828
Using prime factorizations (84=22×3×784 = 2^2 \times 3 \times 7 and 140=22×5×7140 = 2^2 \times 5 \times 7), the common prime factors are 222^2 and 77. Multiplying these yields 4×7=284 \times 7 = 28.
4
Determine the least common multiple (LCM) of 2,3,4,2, 3, 4, and 55.
6060
The LCM must include the highest power of each prime factor present in the numbers: 222^2 (from 44), 313^1, and 515^1. 4×3×5=604 \times 3 \times 5 = 60.
5
Order the evaluated results from least to greatest.
16<21<28<6016 < 21 < 28 < 60
Sorting the calculated values provides the final correct arrangement of the mathematical statements.

Anahtar Kavram

Applying Prime Factorization to Calculate Factor Counts, GCF, and LCM

Alternatif Yöntem

Instead of full prime factorization for the GCF, the Euclidean algorithm can be used: 140−84=56140 - 84 = 56. Next, 84−56=2884 - 56 = 28. Next, 56−28=2856 - 28 = 28. The GCF is 2828.
Tahmini Süre:2m 30s
Soru 60Soru →

If 15%15\% of yy is equal to 25%25\% of 180180, what is the value of yy?

Cevabı ve açıklamayı göster

Cevap: 300

Cevap

The correct value of yy is 300300.
The wording translates to the algebraic equation 0.15y=0.25×1800.15y = 0.25 \times 180. First, evaluate the right side: 25%25\% of 180180 is 4545. The equation simplifies to 0.15y=450.15y = 45. To find the value of yy, divide 4545 by 0.150.15, which yields 300300.

Adım Adım Çözüm

1
Translate the problem statement into an algebraic equation.
0.15y=0.25×1800.15y = 0.25 \times 180
'15%15\% of yy' translates to 0.15y0.15y, and '25%25\% of 180180' translates to 0.25×1800.25 \times 180.
2
Calculate 25%25\% of 180180.
0.25×180=450.25 \times 180 = 45
Simplifying the right side of the equation makes it easier to isolate the variable.
3
Solve for yy by dividing both sides by 0.150.15.
y=450.15=300y = \frac{45}{0.15} = 300
Dividing by the coefficient of yy isolates the variable and provides the final answer.

Anahtar Kavram

Finding an unknown base using algebraic translation of percentage equations.
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