Nokea
Find x if 40:5 = 60:x.
- A. 12
- B. 7
- C. 1
- D. 8
Correct Answer: B
Rationale: To find x in the proportion 40:5 = 60:x, set up the equation: 40/5 = 60/x. Cross-multiply to solve for x: 40x = 60 * 5 => 40x = 300. Divide by 40 to isolate x: x = 300 / 40 = 7.5. However, x should be a whole number since it represents a quantity, so x = 7. Therefore, the correct answer is 7 (B). Choices A, C, and D are incorrect as they do not satisfy the proportion equation.
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30 1/2 - 13 3/4 = ?
- A. 16 3/4
- B. 17
- C. 15 1/4
- D. 15
Correct Answer: A
Rationale: To solve the expression 30 1/2 - 13 3/4, first convert the mixed numbers to improper fractions. 30 1/2 is equivalent to 61/2 and 13 3/4 is equivalent to 55/4. Subtracting 55/4 from 61/2 gives 16 3/4, which is the correct answer. Choice B (17) is incorrect as the correct answer is a mixed number, not a whole number. Choice C (15 1/4) is incorrect as it doesn't result from subtracting the given fractions. Choice D (15) is incorrect; the correct answer is greater than 15.
The height of a building is 150 feet. If each floor of the building is 12 feet high, how many floors are in the building?
- A. 13 floors
- B. 15 floors
- C. 10 floors
- D. 18 floors
Correct Answer: A
Rationale: To determine the number of floors in the building, divide the total height of the building (150 feet) by the height of each floor (12 feet). 150 feet · 12 feet per floor = 12.5 floors. Since floors cannot be in fractions, the answer is rounded down to the nearest whole number, which is 13 floors. Therefore, the correct answer is A: 13 floors. Choice B (15 floors) is incorrect because the calculation results in 12.5 floors, which should be rounded down. Choices C (10 floors) and D (18 floors) are incorrect as they do not accurately reflect the division result and rounding down process.
An office manager makes photocopies for the entire staff each day. At the end of the week, she finds that the photocopy machine has made a total of 3,475 copies. If 6 people used the copier and each person made the same number of copies, how many copies did each person make?
- A. 579 copies
- B. 680 copies
- C. 670 copies
- D. 585 copies
Correct Answer: A
Rationale: To find out how many copies each person made, divide the total number of copies made (3,475) by the number of people who used the copier (6). This gives 579 copies per person (3,475 · 6 = 579). Therefore, each person made 579 copies. Choices B, C, and D are incorrect as they do not result from the correct division of the total number of copies by the number of people who used the copier.
If 30% of a given number is 18, what is the full number?
- A. 60
- B. 30
- C. 40
- D. 45
Correct Answer: A
Rationale: If 30% of a number is 18, you can find the full number by dividing 18 by 0.30 (the decimal equivalent of 30%). This calculation results in 60. Therefore, the full number is 60. Choice B (30) is the result if 30% of the number itself was calculated, not the full number. Choices C (40) and D (45) are incorrect and do not align with the given information.
What is 39 · 8 · 7/6?
- A. 56/39
- B. 39/8
- C. 4 & 7/8
- D. 5 & 8/14
Correct Answer: A
Rationale: To solve the division problem, we need to remember the rule 'Dividing by a fraction is the same as multiplying by its reciprocal.' Therefore, 39 · 8 · 7/6 is equivalent to 39 · 8 6/7. Simplifying this gives (39 6) · (8 7) = 234 · 56 = 56/39. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not correctly simplify the given division problem.