Which of the following inequalities is correct?
- A. 2/3 < 3/5 < 5/7
- B. 2/3 < 5/7 < 3/5
- C. 3/5 < 2/3 < 5/7
- D. 3/5 < 5/7 < 2/3
Correct Answer & Rationale
Correct Answer: C
To determine the order of the fractions, we can convert them to decimals or find a common denominator. - **Option A (2/3 < 3/5 < 5/7)** is incorrect because 2/3 (approximately 0.67) is greater than 3/5 (0.6), violating the first inequality. - **Option B (2/3 < 5/7 < 3/5)** is also incorrect, as 5/7 (approximately 0.71) is greater than 2/3, making the first inequality false. - **Option D (3/5 < 5/7 < 2/3)** is incorrect because, while 3/5 is less than 5/7, 5/7 is greater than 2/3, contradicting the second inequality. - **Option C (3/5 < 2/3 < 5/7)** is accurate; 3/5 is indeed less than 2/3, and 2/3 is less than 5/7, maintaining the correct order.
To determine the order of the fractions, we can convert them to decimals or find a common denominator. - **Option A (2/3 < 3/5 < 5/7)** is incorrect because 2/3 (approximately 0.67) is greater than 3/5 (0.6), violating the first inequality. - **Option B (2/3 < 5/7 < 3/5)** is also incorrect, as 5/7 (approximately 0.71) is greater than 2/3, making the first inequality false. - **Option D (3/5 < 5/7 < 2/3)** is incorrect because, while 3/5 is less than 5/7, 5/7 is greater than 2/3, contradicting the second inequality. - **Option C (3/5 < 2/3 < 5/7)** is accurate; 3/5 is indeed less than 2/3, and 2/3 is less than 5/7, maintaining the correct order.
Other Related Questions
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%) is incorrect as it underestimates the relationship between the two numbers. Option C (111%) slightly overestimates the value, while Option D (115%) significantly exaggerates it. Each of these options fails to accurately represent the proportion of 165 to 150, reinforcing that 110% is the precise measure of this relationship.
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%) is incorrect as it underestimates the relationship between the two numbers. Option C (111%) slightly overestimates the value, while Option D (115%) significantly exaggerates it. Each of these options fails to accurately represent the proportion of 165 to 150, reinforcing that 110% is the precise measure of this relationship.
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.
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.
4/9 (3/16 - 1/12) =
- A. 5/108
- B. 5/48
- C. 2/9
- D. 20/48
Correct Answer & Rationale
Correct Answer: A
To solve \( \frac{4}{9} \left( \frac{3}{16} - \frac{1}{12} \right) \), first calculate \( \frac{3}{16} - \frac{1}{12} \). Finding a common denominator (48), we convert the fractions: \( \frac{3}{16} = \frac{9}{48} \) and \( \frac{1}{12} = \frac{4}{48} \). Thus, \( \frac{9}{48} - \frac{4}{48} = \frac{5}{48} \). Next, multiply \( \frac{4}{9} \) by \( \frac{5}{48} \): \[ \frac{4 \times 5}{9 \times 48} = \frac{20}{432} = \frac{5}{108} \] Option B (5/48) is incorrect as it misrepresents the multiplication step. Option C (2/9) ignores the subtraction and multiplication entirely. Option D (20/48) fails to simplify the fraction correctly.
To solve \( \frac{4}{9} \left( \frac{3}{16} - \frac{1}{12} \right) \), first calculate \( \frac{3}{16} - \frac{1}{12} \). Finding a common denominator (48), we convert the fractions: \( \frac{3}{16} = \frac{9}{48} \) and \( \frac{1}{12} = \frac{4}{48} \). Thus, \( \frac{9}{48} - \frac{4}{48} = \frac{5}{48} \). Next, multiply \( \frac{4}{9} \) by \( \frac{5}{48} \): \[ \frac{4 \times 5}{9 \times 48} = \frac{20}{432} = \frac{5}{108} \] Option B (5/48) is incorrect as it misrepresents the multiplication step. Option C (2/9) ignores the subtraction and multiplication entirely. Option D (20/48) fails to simplify the fraction correctly.