Alexia, Bob, and Comelia recorded the number of pages of books they read last month. Alexia read 135 pages, Bob read 26 pages less than Alexia, and Comelia read 3 and one-half times more pages than Alexia and Bob combined. Which of the following represents the total number of pages that Alexia, Bob, and Comelia read last month?
- A. 3.5(135 + 26)
- B. 3.5[2(135) - 26]
- C. 4.5[2(135) - 26]
- D. 4.5[2(135) + 26]
Correct Answer & Rationale
Correct Answer: C
To determine the total number of pages read, first calculate Bob's pages: he read 135 - 26 = 109 pages. The combined pages of Alexia and Bob is 135 + 109 = 244 pages. Comelia read 3.5 times this total, resulting in 3.5 × 244. Option A incorrectly uses 135 + 26, which does not account for Bob's actual pages read. Option B mistakenly uses a subtraction instead of addition for the combined total. Option D incorrectly adds Bob's pages instead of using the correct combined total for Comelia's calculation. Thus, C accurately represents the total with 3.5(244), leading to the correct final total.
To determine the total number of pages read, first calculate Bob's pages: he read 135 - 26 = 109 pages. The combined pages of Alexia and Bob is 135 + 109 = 244 pages. Comelia read 3.5 times this total, resulting in 3.5 × 244. Option A incorrectly uses 135 + 26, which does not account for Bob's actual pages read. Option B mistakenly uses a subtraction instead of addition for the combined total. Option D incorrectly adds Bob's pages instead of using the correct combined total for Comelia's calculation. Thus, C accurately represents the total with 3.5(244), leading to the correct final total.
Other Related Questions
3 × (1/2 + 1/3) =
- A. 2,1/2
- B. 2,5/6
- C. 3,1/6
- D. 3,5/6
Correct Answer & Rationale
Correct Answer: A
To solve 3 × (1/2 + 1/3), first find a common denominator for the fractions 1/2 and 1/3, which is 6. This gives us (3/6 + 2/6) = 5/6. Multiplying by 3 results in 3 × (5/6) = 15/6, which simplifies to 2 1/2 (Option A). Option B (2 5/6) incorrectly adds an extra fraction. Option C (3 1/6) miscalculates the multiplication. Option D (3 5/6) also misinterprets the original problem, leading to an incorrect total. Thus, only Option A accurately represents the solution.
To solve 3 × (1/2 + 1/3), first find a common denominator for the fractions 1/2 and 1/3, which is 6. This gives us (3/6 + 2/6) = 5/6. Multiplying by 3 results in 3 × (5/6) = 15/6, which simplifies to 2 1/2 (Option A). Option B (2 5/6) incorrectly adds an extra fraction. Option C (3 1/6) miscalculates the multiplication. Option D (3 5/6) also misinterprets the original problem, leading to an incorrect total. Thus, only Option A accurately represents the solution.
165 is what percent of 150?
- A. 95%
- B. 110%
- C. 111%
- D. 115%
Correct Answer & Rationale
Correct Answer: B
To find what percent 165 is of 150, divide 165 by 150 and then multiply by 100. This calculation yields 110%, indicating that 165 is 110% of 150. Option A (95%) underestimates the value, as it suggests 165 is less than 150. Option C (111%) slightly overestimates the percentage, as it does not accurately reflect the calculation. Option D (115%) also exaggerates the value, implying that 165 exceeds 150 by a larger margin than it actually does. Therefore, 110% is the precise representation of 165 in relation to 150.
To find what percent 165 is of 150, divide 165 by 150 and then multiply by 100. This calculation yields 110%, indicating that 165 is 110% of 150. Option A (95%) underestimates the value, as it suggests 165 is less than 150. Option C (111%) slightly overestimates the percentage, as it does not accurately reflect the calculation. Option D (115%) also exaggerates the value, implying that 165 exceeds 150 by a larger margin than it actually does. Therefore, 110% is the precise representation of 165 in relation to 150.
2,3/8 + 5,5/6 =
- A. 7,5/24
- B. 7,4/7
- C. 8,5/24
- D. 8,4/7
Correct Answer & Rationale
Correct Answer: C
To solve 2,3/8 + 5,5/6, first convert the mixed numbers into improper fractions. For 2,3/8, this becomes (2 * 8 + 3)/8 = 19/8. For 5,5/6, it is (5 * 6 + 5)/6 = 35/6. Next, find a common denominator, which is 24. Convert the fractions: 19/8 becomes 57/24, and 35/6 becomes 140/24. Adding these gives 197/24, which converts back to a mixed number as 8,5/24. Options A and B do not match this result. Option D, while close, inaccurately represents the fraction.
To solve 2,3/8 + 5,5/6, first convert the mixed numbers into improper fractions. For 2,3/8, this becomes (2 * 8 + 3)/8 = 19/8. For 5,5/6, it is (5 * 6 + 5)/6 = 35/6. Next, find a common denominator, which is 24. Convert the fractions: 19/8 becomes 57/24, and 35/6 becomes 140/24. Adding these gives 197/24, which converts back to a mixed number as 8,5/24. Options A and B do not match this result. Option D, while close, inaccurately represents the fraction.
If 3 < a < 7 < b, which of the following must be greater than 20?
- A. a²
- B. 2b
- C. ab
- D. b + a
Correct Answer & Rationale
Correct Answer: C
To determine which option must be greater than 20, we analyze each one based on the inequalities provided (3 < a < 7 < b). **Option A: a²** Since a is less than 7, the maximum value for a² is 49 (when a=7), and the minimum value is 16 (when a=4). Thus, a² can be less than 20. **Option B: 2b** With b being greater than 7, the minimum value for 2b is 16 (when b=8). Therefore, 2b can also be less than 20. **Option C: ab** Given a is at least 4 and b is at least 8, the minimum value of ab is 32 (4*8). This must be greater than 20. **Option D: b + a** The minimum value for b + a is 11 (when a=4 and b=7), which is less than 20. Thus, only ab must consistently exceed 20.
To determine which option must be greater than 20, we analyze each one based on the inequalities provided (3 < a < 7 < b). **Option A: a²** Since a is less than 7, the maximum value for a² is 49 (when a=7), and the minimum value is 16 (when a=4). Thus, a² can be less than 20. **Option B: 2b** With b being greater than 7, the minimum value for 2b is 16 (when b=8). Therefore, 2b can also be less than 20. **Option C: ab** Given a is at least 4 and b is at least 8, the minimum value of ab is 32 (4*8). This must be greater than 20. **Option D: b + a** The minimum value for b + a is 11 (when a=4 and b=7), which is less than 20. Thus, only ab must consistently exceed 20.