What is 0.3 percent of 90?
- A. 0.027
- B. 0.27
- C. 0.3
- D. 2.7
Correct Answer & Rationale
Correct Answer: B
To find 0.3 percent of 90, convert the percentage to a decimal by dividing by 100, resulting in 0.003. Then, multiply 0.003 by 90, yielding 0.27. Option A (0.027) is too small, as it miscalculates the multiplication. Option C (0.3) represents the percentage itself, not the calculated value of 0.3 percent of 90. Option D (2.7) is ten times larger than the correct answer, indicating a misunderstanding of the percent calculation. Thus, B (0.27) accurately represents 0.3 percent of 90.
To find 0.3 percent of 90, convert the percentage to a decimal by dividing by 100, resulting in 0.003. Then, multiply 0.003 by 90, yielding 0.27. Option A (0.027) is too small, as it miscalculates the multiplication. Option C (0.3) represents the percentage itself, not the calculated value of 0.3 percent of 90. Option D (2.7) is ten times larger than the correct answer, indicating a misunderstanding of the percent calculation. Thus, B (0.27) accurately represents 0.3 percent of 90.
Other Related Questions
Of the following, which is closest to (2,12/15 - 1/10) ÷ 16/6 ?
- B. 1
- C. 2
- D. 3
Correct Answer & Rationale
Correct Answer: B
To solve (2, 12/15 - 1/10) ÷ (16/6), first, convert the mixed number 2, 12/15 to an improper fraction: 2 = 30/15, so 2, 12/15 = 30/15 + 12/15 = 42/15. Next, simplify 12/15 - 1/10. Finding a common denominator (30), we have 24/30 - 3/30 = 21/30, which simplifies to 7/10. Thus, we compute (42/15 - 7/10) = (28/10 - 21/30) = (84/30 - 21/30) = 63/30 = 21/10. Dividing by (16/6) equals (21/10) ÷ (8/3) = (21/10) × (3/8) = 63/80, which is closest to 1. Options C and D (2 and 3) are incorrect as they overshoot the calculated value, while option B (1) accurately reflects the result of the division.
To solve (2, 12/15 - 1/10) ÷ (16/6), first, convert the mixed number 2, 12/15 to an improper fraction: 2 = 30/15, so 2, 12/15 = 30/15 + 12/15 = 42/15. Next, simplify 12/15 - 1/10. Finding a common denominator (30), we have 24/30 - 3/30 = 21/30, which simplifies to 7/10. Thus, we compute (42/15 - 7/10) = (28/10 - 21/30) = (84/30 - 21/30) = 63/30 = 21/10. Dividing by (16/6) equals (21/10) ÷ (8/3) = (21/10) × (3/8) = 63/80, which is closest to 1. Options C and D (2 and 3) are incorrect as they overshoot the calculated value, while option B (1) accurately reflects the result of the division.
Which of the following integers, when rounded to the nearest thousand, results in 2,000?
- A. 2,567
- B. 1,499
- C. 1,097
- D. 1,601
Correct Answer & Rationale
Correct Answer: d
When rounding to the nearest thousand, we look at the hundreds digit. If it is 5 or higher, we round up; if it is 4 or lower, we round down. Option D (1,601) rounds to 2,000 because the hundreds digit (6) is greater than 5, leading to an increase in the thousands place. Option A (2,567) rounds to 3,000, as the hundreds digit (5) prompts rounding up. Option B (1,499) rounds to 1,000 since the hundreds digit (4) indicates rounding down. Option C (1,097) also rounds to 1,000 for the same reason as B. Thus, only D rounds to 2,000.
When rounding to the nearest thousand, we look at the hundreds digit. If it is 5 or higher, we round up; if it is 4 or lower, we round down. Option D (1,601) rounds to 2,000 because the hundreds digit (6) is greater than 5, leading to an increase in the thousands place. Option A (2,567) rounds to 3,000, as the hundreds digit (5) prompts rounding up. Option B (1,499) rounds to 1,000 since the hundreds digit (4) indicates rounding down. Option C (1,097) also rounds to 1,000 for the same reason as B. Thus, only D rounds to 2,000.
Kayla has a stack of photographs that is 20 centimeters high. If each photograph is 0.04 cm thick, how many photos are there in the stack?
- A. 8
- B. 50
- C. 80
- D. 500
Correct Answer & Rationale
Correct Answer: D
To determine the number of photographs in the stack, divide the total height of the stack by the thickness of each photograph. The stack is 20 cm high and each photograph is 0.04 cm thick. Calculating this gives: 20 cm ÷ 0.04 cm = 500 photographs. Option A (8) is incorrect as it underestimates the total by not accounting for the thickness appropriately. Option B (50) also miscalculates the total, suggesting a much smaller number of photographs. Option C (80) is an overestimation, failing to consider the correct division of height by thickness. Only option D (500) accurately reflects the calculation, confirming the total number of photographs in the stack.
To determine the number of photographs in the stack, divide the total height of the stack by the thickness of each photograph. The stack is 20 cm high and each photograph is 0.04 cm thick. Calculating this gives: 20 cm ÷ 0.04 cm = 500 photographs. Option A (8) is incorrect as it underestimates the total by not accounting for the thickness appropriately. Option B (50) also miscalculates the total, suggesting a much smaller number of photographs. Option C (80) is an overestimation, failing to consider the correct division of height by thickness. Only option D (500) accurately reflects the calculation, confirming the total number of photographs in the stack.
2/3 (6 + 1/2) =
- A. 4,1/3
- B. 4,1/2
- C. 5,1/2
- D. 6,1/3
Correct Answer & Rationale
Correct Answer: A
To solve \( \frac{2}{3}(6 + \frac{1}{2}) \), start by simplifying the expression inside the parentheses. \( 6 + \frac{1}{2} \) equals \( 6.5 \) or \( \frac{13}{2} \). Next, multiply \( \frac{2}{3} \) by \( \frac{13}{2} \): \[ \frac{2}{3} \times \frac{13}{2} = \frac{2 \times 13}{3 \times 2} = \frac{13}{3} = 4 \frac{1}{3} \] Option A is accurate. Option B (4,1/2) incorrectly adds an extra half. Option C (5,1/2) miscalculates the multiplication and addition. Option D (6,1/3) mistakenly assumes a higher total before multiplication.
To solve \( \frac{2}{3}(6 + \frac{1}{2}) \), start by simplifying the expression inside the parentheses. \( 6 + \frac{1}{2} \) equals \( 6.5 \) or \( \frac{13}{2} \). Next, multiply \( \frac{2}{3} \) by \( \frac{13}{2} \): \[ \frac{2}{3} \times \frac{13}{2} = \frac{2 \times 13}{3 \times 2} = \frac{13}{3} = 4 \frac{1}{3} \] Option A is accurate. Option B (4,1/2) incorrectly adds an extra half. Option C (5,1/2) miscalculates the multiplication and addition. Option D (6,1/3) mistakenly assumes a higher total before multiplication.