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.
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What is the result of the expression 4/5 + 6/7?
- A. 1 23/35
- B. 2 5/7
- C. 1 1/7
- D. 1 3/4
Correct Answer: A
Rationale: To add fractions with different denominators, you first need to find a common denominator. In this case, the common denominator for 5 and 7 is 35. Then, convert each fraction to have a denominator of 35. 4/5 becomes 28/35, and 6/7 becomes 30/35. Adding these fractions together gives 58/35, which simplifies to 1 23/35. Therefore, the correct answer is A, 1 23/35. Choice B, 2 5/7, is incorrect because it does not match the correct result. Choice C, 1 1/7, is incorrect as it is not the simplified form of the sum of the fractions. Choice D, 1 3/4, is incorrect as it is a different result and not the sum of 4/5 and 6/7.
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.
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.
Convert the decimal 0.98 to a percent.
- A. 98%
- B. 9%
- C. 98
- D. 99%
Correct Answer: A
Rationale: To convert a decimal to a percent, you multiply the decimal by 100. In this case, 0.98 100 = 98%. Therefore, the correct answer is A, which is 98%. Choice B (9%) is incorrect as it results from an error in calculation. Choice C (98) is incorrect as it lacks the percent symbol. Choice D (99%) is incorrect as it is not the equivalent percentage of 0.98.
What is (12/15) · (3/5) = ?
- A. 1 1/3
- B. 1 2/3
- C. 2 1/3
- D. 1
Correct Answer: A
Rationale: To divide fractions, you multiply by the reciprocal of the divisor. (12/15) · (3/5) is the same as (12/15) * (5/3). Cancel out common factors to simplify: 12 · 3 = 4, 15 · 5 = 3. So, the expression simplifies to 4/3, which is 1 1/3 in mixed number form. Choice A, 1 1/3, is the correct answer. Choices B, C, and D are incorrect because they do not represent the simplified form of the division of the given fractions.