Number Theory and Operations

159 soru

Soru 81Soru →

Consider the process of evaluating the numerical expression below using the standard order of operations:

14+3×(7−22)−8÷4 14 + 3 \times (7 - 2^2) - 8 \div 4

How should the following intermediate simplified forms be arranged to represent the exact chronological sequence of the step-by-step evaluation?

Öğeleri doğru sıraya koymak için sürükleyin

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Cevap

The expressions should be ordered starting with the exponent evaluation, followed by the parentheses, then multiplication and division, and finally addition.
The proper application of the order of operations (PEMDAS/BODMAS) ensures that we first simplify inside the parentheses (handling the exponent first, then subtraction), next process multiplication and division from left to right, and finally address addition and subtraction from left to right. This produces the exact sequence of intermediate expressions shown in the correct arrangement.

Adım Adım Çözüm

1
Evaluate the exponent inside the grouping symbols.
222^2 simplifies to 44, changing the expression to 14+3×(7−4)−8÷414 + 3 \times (7 - 4) - 8 \div 4.
Order of operations dictates that exponents inside parentheses take precedence over other operations.
2
Complete the operation inside the parentheses.
7−47 - 4 simplifies to 33, yielding 14+3×3−8÷414 + 3 \times 3 - 8 \div 4.
All operations within grouping symbols must be fully resolved before proceeding to external operations.
3
Evaluate multiplication and division.
3×33 \times 3 becomes 99 and 8÷48 \div 4 becomes 22, resulting in 14+9−214 + 9 - 2.
Multiplication and division share the same priority and are executed from left to right before addition or subtraction.
4
Perform the addition.
14+914 + 9 becomes 2323, leaving 23−223 - 2.
Addition and subtraction share the lowest priority and are evaluated from left to right.
5
Perform the final subtraction.
23−223 - 2 simplifies to the final answer of 2121.
This is the final remaining mathematical operation.

Anahtar Kavram

Order of Operations (PEMDAS)
Soru 82Soru →

Determine the final inventory count and the net percentage change by filling in the blanks.

Aşağıdaki boşlukları doldurun

A military supply depot initially stored 5,0005,000 tactical vests. During a regional exercise, the inventory was reduced by 30%30\%. Afterward, a new shipment increased the remaining stock by 40%40\%. The depot now holds tactical vests. Compared to the original inventory, this represents a net of \%.
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Cevap

The depot now holds 4,900 vests, representing a net decrease of 2%.
The final inventory is 4,9004,900 vests, which is 100100 vests fewer than the original 5,0005,000. This equates to a net decrease of 2%2\%. In successive percentage problems, it is crucial to recalculate the base amount for each step.

Adım Adım Çözüm

1
Calculate the inventory after the initial 30%30\% reduction.
5,000−(0.30×5,000)=5,000−1,500=3,5005,000 - (0.30 \times 5,000) = 5,000 - 1,500 = 3,500 vests.
The first event reduces the starting stock by 30%30\%, establishing a new base amount for the subsequent calculation.
2
Calculate the inventory after the 40%40\% increase.
3,500+(0.40×3,500)=3,500+1,400=4,9003,500 + (0.40 \times 3,500) = 3,500 + 1,400 = 4,900 vests.
The 40%40\% increase applies only to the remaining stock (3,5003,500), not the original 5,0005,000.
3
Determine the net change from the original inventory.
5,000−4,900=1005,000 - 4,900 = 100 vests fewer than the original.
Comparing the final inventory (4,9004,900) to the original inventory (5,0005,000) reveals a net decrease.
4
Calculate the net percentage change.
(1005,000)×100%=0.02×100%=2%(\frac{100}{5,000}) \times 100\% = 0.02 \times 100\% = 2\%.
The percentage change is found by dividing the absolute change by the original base amount, then multiplying by 100%100\%.

Anahtar Kavram

Successive Percentages and Changing Base Values
Soru 83Soru →

What is the smallest positive integer that is a multiple of both 88 and 1212?

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Cevap: 24

Cevap

24
The smallest positive integer that is a multiple of both 88 and 1212 is their least common multiple (LCM). The multiples of 88 are 8,16,24,32,…8, 16, 24, 32, \dots and the multiples of 1212 are 12,24,36,…12, 24, 36, \dots. The smallest number that appears in both lists is 2424.

Adım Adım Çözüm

1
Find the positive multiples of 88.
8,16,24,32,40,…8, 16, 24, 32, 40, \dots
We need to determine a number that is a multiple of 88.
2
Find the positive multiples of 1212.
12,24,36,48,…12, 24, 36, 48, \dots
We need the number to also be a multiple of 1212.
3
Identify the smallest common multiple from both lists.
2424
The question asks for the smallest positive integer that is a multiple of both numbers.

Anahtar Kavram

Least Common Multiple (LCM)
Tahmini Süre:45s
Soru 84Soru →

In a medical supply drop, the ratio of bandages to antiseptic bottles is 7:37:3. If there are 210210 antiseptic bottles in the drop, how many bandages are included?

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Cevap: 490

Cevap

490
The proportion must match the quantity of bandages to antiseptics. Since the ratio is 77 parts bandages for every 33 parts antiseptics, and the actual number of antiseptics is 210210 (7070 times the ratio amount), the number of bandages must also be 7070 times its ratio amount. Therefore, 7×70=4907 \times 70 = 490 bandages.

Adım Adım Çözüm

1
Identify the known ratio and the known quantity.
The ratio of bandages to antiseptics is 7:37:3, and there are 210210 antiseptics.
To correctly set up a mathematically accurate proportion.
2
Set up the proportion equation.
73=x210\frac{7}{3} = \frac{x}{210}
To relate the given simplified ratio to the actual numbers.
3
Solve the proportion for xx.
x=7×2103=7×70=490x = \frac{7 \times 210}{3} = 7 \times 70 = 490
To find the unknown number of bandages.

Anahtar Kavram

Solving basic proportions from a given part-to-part ratio
Tahmini Süre:45s
Soru 85Soru →

A carpenter has two pieces of wood. One piece is 1818 inches long and the other is 2424 inches long. She wants to cut both pieces into smaller segments of equal length with no wood left over. What is the greatest possible length, in inches, of each segment?

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Cevap: 6

Cevap

The greatest possible length of each segment is 6 inches.
To find the greatest possible length for the cut segments, we must find the greatest common factor (GCF) of 18 and 24. The factors of 18 are 1, 2, 3, 6, 9, 18. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24. The largest number appearing in both lists is 6, making it the correct answer.

Adım Adım Çözüm

1
Identify the goal of the problem.
We need to divide both 18 and 24 into equal segments of the maximum possible length. This means finding the Greatest Common Factor (GCF) of 18 and 24.
The phrase 'cut into equal length' implies finding a common factor, and 'greatest possible length' specifies the GCF.
2
List the factors of 18.
The factors of 18 are 1, 2, 3, 6, 9, and 18.
These are all the integers that divide evenly into 18.
3
List the factors of 24.
The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24.
These are all the integers that divide evenly into 24.
4
Identify the greatest factor common to both lists.
The common factors are 1, 2, 3, and 6. The greatest among these is 6.
This is the largest segment size that will evenly divide both pieces of wood.

Anahtar Kavram

The Greatest Common Factor (GCF) is the largest positive integer that divides evenly into two or more given numbers. It is commonly used when splitting items into equal, maximum-sized groups.
Tahmini Süre:1m 0s
Soru 86Soru →

A pilot logs 120120 flight hours during the first quarter of the year. If this amount represents 40%40\% of their annual flight hour requirement, how many additional flight hours must the pilot complete by the end of the year to exactly meet the requirement?

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Cevap: 180

Cevap

The pilot must complete 180 additional flight hours.
The correct answer is found by first determining the total annual requirement. Since 120 hours represents 40% of the total, the total is calculated by dividing 120 by 0.40, which equals 300 hours. The question asks for the additional hours needed, so you must subtract the 120 hours already flown from the 300 total hours, leaving exactly 180 hours.

Adım Adım Çözüm

1
Set up an equation to find the total annual flight hour requirement.
0.40×Total=1200.40 \times \text{Total} = 120
The problem states that 120 hours is exactly 40% of the full annual requirement.
2
Solve for the total annual requirement by dividing the completed hours by the decimal percentage.
Total=1200.40=300\text{Total} = \frac{120}{0.40} = 300 hours
Dividing the part by the percentage (as a decimal) yields the whole base amount.
3
Subtract the hours already flown from the total annual requirement to find the remaining hours needed.
300−120=180300 - 120 = 180 hours
The question specifically asks for the 'additional' flight hours required to finish the year.

Anahtar Kavram

Reverse Percentage and Successive Subtraction
Soru 87Soru →

During a field exercise, a combat engineer platoon's daily fuel consumption increased by 20%20\% in the first week, and then decreased by 25%25\% in the second week. If the final fuel consumption was 4,5004,500 gallons per day, what was the initial daily fuel consumption in gallons?

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Cevap: 5000

Cevap

5000
The correct calculation requires treating the percentage changes as sequential multipliers. The initial amount increases by 20%20\% (multiplier of 1.201.20) and the new amount decreases by 25%25\% (multiplier of 0.750.75). The combined net multiplier is 1.20×0.75=0.901.20 \times 0.75 = 0.90, meaning the final value is 90%90\% of the initial value. To find the initial value, we divide the final amount (4,5004,500) by 0.900.90, which yields 5,0005,000.

Adım Adım Çözüm

1
Determine the multipliers for the successive percentage changes.
A 20%20\% increase is represented by 1.201.20, and a 25%25\% decrease is represented by 0.750.75.
Successive percentage changes must be multiplied consecutively, not added together.
2
Set up an equation representing the net change.
x×1.20×0.75=4500x \times 1.20 \times 0.75 = 4500
The initial amount (xx) multiplied by each successive change equals the final amount.
3
Calculate the combined multiplier.
1.20×0.75=0.901.20 \times 0.75 = 0.90
Simplifying the multipliers shows that the net change is a 10%10\% decrease overall.
4
Solve the equation for the initial amount.
x=45000.90=5000x = \frac{4500}{0.90} = 5000
Dividing the final consumption by the combined multiplier isolates xx to find the original amount.

Anahtar Kavram

Successive Percentage Changes and Reverse Percentages
Soru 88Soru →

Let xx be a negative even integer and yy be a negative odd integer. Which of the following expressions will always result in a positive odd integer?

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Cevap: x×y+1x \times y + 1

Cevap

x×y+1x \times y + 1
When multiplying two negative integers, the result is positive. When multiplying an even integer by an odd integer, the result is always even. Therefore, the product of xx and yy is a positive even integer. Adding 1 to any even integer results in an odd integer. Thus, the expression always yields a positive odd integer.

Adım Adım Çözüm

1
Determine the sign and parity of the product x×yx \times y.
x×yx \times y is a positive even integer.
Multiplying two negative numbers yields a positive number. Multiplying an even number by any integer yields an even number.
2
Evaluate the result of adding 1 to the product.
x×y+1x \times y + 1 is a positive odd integer.
Adding 1 to any even integer changes its parity to odd. Adding 1 to a positive number keeps it positive.
3
Check the validity of the other provided expressions.
Only x×y+1x \times y + 1 guarantees a positive odd result.
Other expressions result in negative odd values, positive even values, or values that can fluctuate in sign based on specific magnitudes.

Anahtar Kavram

Parity and Sign Properties of Integers
Soru 89Soru →

What is the value of the following expression?

34+12÷23−18\frac{3}{4} + \frac{1}{2} \div \frac{2}{3} - \frac{1}{8}
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Cevap: 1381 \frac{3}{8}

Cevap

The correct answer is 1381 \frac{3}{8}.
The correct answer is found by first performing the division operation (which becomes 3/43/4), then finding a common denominator (8) to add and subtract the remaining fractions. This yields 11/811/8, which simplifies to 1381 \frac{3}{8}.

Adım Adım Çözüm

1
Evaluate the division portion of the expression first according to the order of operations.
12÷23=12×32=34\frac{1}{2} \div \frac{2}{3} = \frac{1}{2} \times \frac{3}{2} = \frac{3}{4}
The order of operations requires division to be performed before addition or subtraction.
2
Substitute the division result back into the original expression.
34+34−18\frac{3}{4} + \frac{3}{4} - \frac{1}{8}
This updates the expression to contain only addition and subtraction operations.
3
Find the least common multiple (LCM) for the denominators to perform addition and subtraction.
The LCM of 4 and 8 is 8. Converting the fractions yields 68+68−18\frac{6}{8} + \frac{6}{8} - \frac{1}{8}.
Fractions must have a common denominator to be added or subtracted.
4
Perform the addition and subtraction sequentially from left to right.
68+68−18=128−18=118\frac{6}{8} + \frac{6}{8} - \frac{1}{8} = \frac{12}{8} - \frac{1}{8} = \frac{11}{8}
Addition and subtraction carry the same precedence and are evaluated from left to right.
5
Convert the resulting improper fraction into a mixed number.
118=138\frac{11}{8} = 1 \frac{3}{8}
The answer choices are presented as mixed numbers, requiring the improper fraction to be converted.

Anahtar Kavram

Applying the order of operations (PEMDAS) to compound fraction arithmetic.
Soru 90Soru →

A map uses a scale where 3 cm3\text{ cm} represents 20 km20\text{ km}. If two towns are separated by 15 cm15\text{ cm} on the map, what is the actual distance between them in kilometers?

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Cevap: 100100

Cevap

100
The correct answer is determined by setting up a direct proportion between the map distance and the actual distance: 320=15x\frac{3}{20} = \frac{15}{x}. Cross-multiplying yields 3x=3003x = 300. Dividing both sides by 33 isolates xx, resulting in 100 km100\text{ km}. Alternatively, you can observe that the map distance increased by a factor of 55 (3×5=153 \times 5 = 15), so the actual distance must also increase by a factor of 55 (20×5=10020 \times 5 = 100).

Adım Adım Çözüm

1
Identify the given scale ratio from the problem.
The ratio of map distance to actual distance is 3 cm:20 km3\text{ cm} : 20\text{ km}.
This baseline ratio establishes the mathematical relationship needed to find any other actual distance.
2
Set up a proportion matching map measurements to actual measurements.
320=15x\frac{3}{20} = \frac{15}{x}
Keeping the units aligned (map distance in the numerator, actual distance in the denominator) ensures the proportion is solvable.
3
Solve for the unknown actual distance xx using cross-multiplication.
3x=15×20→3x=3003x = 15 \times 20 \rightarrow 3x = 300
Cross-multiplication transforms the proportion into a standard linear equation.
4
Isolate xx by dividing both sides of the equation by 33.
x=3003=100x = \frac{300}{3} = 100
Dividing both sides balances the equation and provides the final actual distance in kilometers.

Anahtar Kavram

Direct Proportions and Scale Factors
Soru 91Soru →

A logistics unit packs 33 boxes of rations for every 44 boxes of water. If they pack 1212 boxes of rations, how many boxes of water do they pack?

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Cevap: 1616

Cevap

1616
The ratio of rations to water is 3 to 4. Since the actual number of rations (12) is exactly 4 times the ratio number (3), the number of water boxes must also be 4 times its corresponding ratio number. Multiplying 4 by 4 yields 16 boxes of water.

Adım Adım Çözüm

1
Set up the proportion comparing rations to water.
34=12x\frac{3}{4} = \frac{12}{x}
This establishes the mathematical relationship between the known ratio and the actual amounts.
2
Determine the scale factor for the rations.
12÷3=412 \div 3 = 4
Finding how many times the base ratio was multiplied to get the actual number of rations.
3
Apply the scale factor to the water portion of the ratio.
4×4=164 \times 4 = 16
To maintain the proportion, both parts of the ratio must be multiplied by the same scale factor.

Anahtar Kavram

Solving basic proportions by finding and applying a scale factor.
Tahmini Süre:45s
Soru 92Soru →

The sum of three consecutive negative even integers is −102-102. What is the absolute value of the smallest of these integers?

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Cevap: 36

Cevap

36
By defining the consecutive even integers algebraically, the smallest integer is correctly identified as −36-36. Taking the absolute value of −36-36 yields 3636.

Adım Adım Çözüm

1
Define variables for the three consecutive even integers.
Let the smallest integer be xx. The next consecutive even integers are x+2x + 2 and x+4x + 4.
Consecutive even integers are always 2 units apart.
2
Set up the equation.
x+(x+2)+(x+4)=−102x + (x + 2) + (x + 4) = -102
The sum of the three integers is given as −102-102.
3
Solve for xx.
3x+6=−1023x + 6 = -102 leads to 3x=−1083x = -108, yielding x=−36x = -36.
Isolating xx provides the value of the smallest integer.
4
Calculate the absolute value.
∣−36∣=36|-36| = 36
The question specifically asks for the absolute value of the smallest integer.

Anahtar Kavram

Consecutive integers and absolute value properties
Soru 93Soru →

A carpenter is cutting a wooden board that is initially 121212 \frac{1}{2} feet long. First, he cuts off a piece that is 3343 \frac{3}{4} feet long and sets it aside. Then, he divides the remaining board into 55 equal sections. What is the length of each of these 55 sections?

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Cevap: 1341 \frac{3}{4} feet

Cevap

Each of the 55 sections has a length of 1341 \frac{3}{4} feet.
The correct sequence of operations is to first determine the remaining length by subtracting 3343 \frac{3}{4} from 121212 \frac{1}{2}, yielding 8348 \frac{3}{4} feet. Then, dividing this remaining length by 55 results in 1341 \frac{3}{4} feet per section.

Adım Adım Çözüm

1
Calculate the length of the remaining board by subtracting the cut piece from the total length.
1212−33412 \frac{1}{2} - 3 \frac{3}{4}
The carpenter first removes a piece, leaving a smaller board to be divided.
2
Find a common denominator to perform the subtraction.
1224−33412 \frac{2}{4} - 3 \frac{3}{4}
Fractions must have the same denominator to be subtracted.
3
Borrow from the whole number to subtract the fractions.
1164−334=83411 \frac{6}{4} - 3 \frac{3}{4} = 8 \frac{3}{4} feet
Since 24\frac{2}{4} is less than 34\frac{3}{4}, one whole unit must be converted into 44\frac{4}{4}.
4
Divide the remaining length by 5 to find the length of each section.
834÷58 \frac{3}{4} \div 5
The remaining board is split into 5 equal parts.
5
Convert the mixed number to an improper fraction and multiply by the reciprocal of 5.
354×15=74=134\frac{35}{4} \times \frac{1}{5} = \frac{7}{4} = 1 \frac{3}{4} feet
Division by a whole number is equivalent to multiplying by its reciprocal.

Anahtar Kavram

Solving multi-step problems involving subtraction and division of mixed numbers with unlike denominators.
Soru 94Soru →

An ammunition crate contains tracer rounds and standard rounds in a ratio of 5:125:12. If the crate holds a total of 510510 rounds, how many tracer rounds does it contain?

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Cevap: 150; 150 rounds; 150 tracer rounds

Cevap

150
By adding the ratio parts (5+12=175 + 12 = 17), we find that tracer rounds make up 517\frac{5}{17} of the total contents. Multiplying the total number of rounds (510510) by this fraction yields 150150 tracer rounds.

Adım Adım Çözüm

1
Calculate the total number of parts in the ratio.
5+12=175 + 12 = 17 total parts.
The total quantity of rounds (510510) corresponds to the combined parts of the ratio.
2
Determine the number of rounds represented by a single part.
510÷17=30510 \div 17 = 30 rounds per part.
Dividing the total items by the total parts finds the scale factor.
3
Calculate the total number of tracer rounds.
5×30=1505 \times 30 = 150 tracer rounds.
The ratio states there are 55 parts of tracer rounds, so we multiply the scale factor by 55.

Anahtar Kavram

Solving part-to-whole problems using a part-to-part ratio.
Soru 95Soru →

A maintenance crew uses 22 gallons of primer for every 55 gallons of paint. If the crew uses 1010 gallons of primer, how many gallons of paint are needed?

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Cevap: 25; 25 gallons; 25 gal

Cevap

25
The given ratio of primer to paint is 2:52:5. Since 1010 gallons of primer is 55 times the original 22 gallons, you must also multiply the 55 gallons of paint by 55 to maintain the ratio. Therefore, 5×5=255 \times 5 = 25 gallons of paint are needed.

Adım Adım Çözüm

1
Set up a proportion using the given ratio of primer to paint.
25=10x\frac{2}{5} = \frac{10}{x}
To relate the base ratio to the actual amounts used, where xx represents the unknown gallons of paint.
2
Solve the proportion for xx.
x=5×102=25x = \frac{5 \times 10}{2} = 25
Using cross-multiplication isolates xx to find the required amount of paint.

Anahtar Kavram

Solving direct proportions
Soru 96Soru →

Arrange the following fractions and mixed numbers in ascending order (from least to greatest).

Öğeleri doğru sıraya koymak için sürükleyin

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Cevap

The correct ascending order is 27122 \frac{7}{12}, 2582 \frac{5}{8}, 83\frac{8}{3}, and 114\frac{11}{4}.
By converting all values to mixed numbers with a common denominator of 24, we find their fractional parts are 1424\frac{14}{24}, 1524\frac{15}{24}, 1624\frac{16}{24}, and 1824\frac{18}{24}. Because all whole numbers are 2, the order of the original fractions matches the ascending order of these fractional parts.

Adım Adım Çözüm

1
Convert the improper fractions to mixed numbers to simplify comparison.
114=234\frac{11}{4} = 2 \frac{3}{4} and 83=223\frac{8}{3} = 2 \frac{2}{3}. The other numbers are already mixed numbers: 2582 \frac{5}{8} and 27122 \frac{7}{12}.
Because all the whole numbers are 2, we only need to compare their fractional parts to determine the order.
2
Identify the least common denominator (LCD) for the fractional parts: 34\frac{3}{4}, 58\frac{5}{8}, 712\frac{7}{12}, and 23\frac{2}{3}.
The denominators are 4, 8, 12, and 3. The lowest number they all divide into evenly is 24.
A common denominator is required to accurately compare the sizes of fractions with unlike denominators.
3
Convert each fractional part to an equivalent fraction with a denominator of 24.
34=1824\frac{3}{4} = \frac{18}{24}, 58=1524\frac{5}{8} = \frac{15}{24}, 712=1424\frac{7}{12} = \frac{14}{24}, and 23=1624\frac{2}{3} = \frac{16}{24}.
Multiplying both the numerator and denominator by the same value preserves the fraction's overall mathematical value.
4
Order the converted fractions from least to greatest based on their numerators.
1424<1524<1624<1824\frac{14}{24} < \frac{15}{24} < \frac{16}{24} < \frac{18}{24}.
When denominators are equal, a larger numerator represents a larger overall value.
5
Match the ordered fractions back to their original given forms.
27122 \frac{7}{12} (from 1424\frac{14}{24}), 2582 \frac{5}{8} (from 1524\frac{15}{24}), 83\frac{8}{3} (from 1624\frac{16}{24}), and 114\frac{11}{4} (from 1824\frac{18}{24}).
The final answer must present the exact numbers provided in the original stem.

Anahtar Kavram

Comparing and Ordering Fractions with Unlike Denominators
Soru 97Soru →

A carpenter has a wooden board that is 5345 \frac{3}{4} inches wide. If he shaves off exactly 18\frac{1}{8} of an inch from the width, what is the new width of the board?

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Cevap: 5585 \frac{5}{8} inches

Cevap

The new width of the board is 5585 \frac{5}{8} inches.
To find the new width, subtract the shaved amount from the original width: 534−185 \frac{3}{4} - \frac{1}{8}. First, find a common denominator, which is 8. Convert 34\frac{3}{4} to 68\frac{6}{8}. Subtracting 18\frac{1}{8} from 5685 \frac{6}{8} gives the correct answer of 5585 \frac{5}{8} inches.

Adım Adım Çözüm

1
Set up the subtraction problem based on the context.
534−185 \frac{3}{4} - \frac{1}{8}
The phrase 'shaves off' indicates subtraction from the original width.
2
Find a common denominator for the fractions 34\frac{3}{4} and 18\frac{1}{8}.
The common denominator is 88.
Fractions must have the same denominator before they can be subtracted.
3
Convert 34\frac{3}{4} to an equivalent fraction with a denominator of 88.
3×24×2=68\frac{3 \times 2}{4 \times 2} = \frac{6}{8}
Multiplying both the numerator and denominator by 22 keeps the fraction's value the same while converting the denominator.
4
Subtract the fractions.
568−18=5585 \frac{6}{8} - \frac{1}{8} = 5 \frac{5}{8}
Subtract the numerators while keeping the common denominator the same.

Anahtar Kavram

Subtracting mixed numbers with unlike denominators
Soru 98Soru →

Which of the following statements about integers is always true?

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Cevap: The difference between any integer and its absolute value is always an even integer.

Cevap

The statement claiming that the difference between any integer and its absolute value is always an even integer.
For any non-negative integer, the difference between the integer and its absolute value is 0, which is an even integer. For any negative integer, the difference evaluates to twice the integer (2x), which is a multiple of 2 and therefore also even. Thus, the statement holds true for all integers.

Adım Adım Çözüm

1
Analyze the behavior of the expression (x - |x|) for non-negative integers.
If x is 0 or positive, |x| = x. Therefore, x - |x| = x - x = 0.
To test the property for the first distinct category of integers.
2
Analyze the behavior of the expression (x - |x|) for negative integers.
If x is negative, |x| = -x. Therefore, x - |x| = x - (-x) = x + x = 2x.
To test the property for the remaining category of integers.
3
Determine the parity (odd/even status) of the results from the previous steps.
The number 0 is an even integer. The expression 2x is inherently a multiple of 2, making it an even integer regardless of the value of x.
To conclude whether the difference is universally even.

Anahtar Kavram

Parity and Absolute Value Properties
Soru 99Soru →

An aviation squadron requires 33 hours of preventive maintenance for every 88 hours of flight time. If a specific helicopter undergoes 2424 hours of preventive maintenance during a given month, what is the total number of hours logged for both flight and maintenance combined?

Cevabı ve açıklamayı göster

Cevap: 8888

Cevap

The total number of hours logged is 8888.
The given ratio of maintenance to flight time is 3:83:8. Because the helicopter had 2424 hours of maintenance, we find the multiplier by dividing 2424 by 33, which is 88. We then apply this multiplier to the flight time ratio (8×8=648 \times 8 = 64 hours). To find the total combined hours, we add the maintenance hours and flight hours together: 24+64=8824 + 64 = 88.

Adım Adım Çözüm

1
Find the scale factor (multiplier) by comparing the actual maintenance hours to the ratio.
24÷3=824 \div 3 = 8
This establishes how many times larger the actual numbers are compared to the base ratio.
2
Calculate the actual flight hours using the scale factor.
8×8=648 \times 8 = 64 hours of flight time
Applying the scale factor to the flight time ratio gives the actual flight time.
3
Add the actual maintenance hours and actual flight hours to find the total time.
24+64=8824 + 64 = 88 total hours
The question specifically asks for the combined total of both flight and maintenance time.

Anahtar Kavram

Solving part-to-part ratio word problems and calculating a total sum.
Soru 100Soru →

A military supply shipment contains 3.4×1043.4 \times 10^4 ready-to-eat meals. What is the total number of meals written in standard numerical form?

Cevabı ve açıklamayı göster

Cevap: 34000

Cevap

34000
The expression 3.4×1043.4 \times 10^4 represents 3.43.4 multiplied by 10,00010,000. Shifting the decimal point 4 places to the right results in exactly 34,00034,000.

Adım Adım Çözüm

1
Identify the exponent on the base 10.
The exponent is 4.
The exponent determines the number of places the decimal point must be shifted.
2
Move the decimal point 4 places to the right.
3.4 becomes 34000.
Multiplying by 10^4 is equivalent to shifting the decimal to the right by 4 places to convert the scientific notation into standard form.

Anahtar Kavram

Converting from scientific notation to standard form involves shifting the decimal point based on the value and sign of the exponent.
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