Marisol has 5 times as many books as Jerry. Jerry has 15 books. How many books does Marisol have?
- A. 10
- B. 20
- C. 75
- D. 225
Correct Answer & Rationale
Correct Answer: C
To determine how many books Marisol has, start by recognizing that she has 5 times the number of books Jerry has. Since Jerry has 15 books, you multiply 15 by 5: 15 × 5 = 75. Thus, Marisol has 75 books. Option A (10) is incorrect as it suggests Marisol has fewer books than Jerry. Option B (20) also underestimates her total, as it does not account for the multiplication factor of 5. Option D (225) overestimates the total by incorrectly multiplying the number of Jerry's books. Only option C accurately reflects the calculation based on the relationship between Marisol's and Jerry's books.
To determine how many books Marisol has, start by recognizing that she has 5 times the number of books Jerry has. Since Jerry has 15 books, you multiply 15 by 5: 15 × 5 = 75. Thus, Marisol has 75 books. Option A (10) is incorrect as it suggests Marisol has fewer books than Jerry. Option B (20) also underestimates her total, as it does not account for the multiplication factor of 5. Option D (225) overestimates the total by incorrectly multiplying the number of Jerry's books. Only option C accurately reflects the calculation based on the relationship between Marisol's and Jerry's books.
Other Related Questions
Which of the following is equivalent to 8,1/4?
- A. 0.0825
- B. 0.825
- C. 8.25
- D. 82.5
Correct Answer & Rationale
Correct Answer: c
To convert the mixed number 8 1/4 into an improper fraction, first multiply the whole number (8) by the denominator (4), resulting in 32. Then, add the numerator (1) to get 33, making the improper fraction 33/4. When you divide 33 by 4, you get 8.25. Option A (0.0825) is incorrect as it represents a much smaller value. Option B (0.825) is also incorrect, as it is less than 1. Option D (82.5) is incorrect, being ten times larger than the correct value. Thus, 8.25 accurately reflects the original mixed number.
To convert the mixed number 8 1/4 into an improper fraction, first multiply the whole number (8) by the denominator (4), resulting in 32. Then, add the numerator (1) to get 33, making the improper fraction 33/4. When you divide 33 by 4, you get 8.25. Option A (0.0825) is incorrect as it represents a much smaller value. Option B (0.825) is also incorrect, as it is less than 1. Option D (82.5) is incorrect, being ten times larger than the correct value. Thus, 8.25 accurately reflects the original mixed number.
A book is on sale for 25% off. If the original price of the book was D dollars, what is the sale price, in dollars, in terms of D?
- A. D - 25
- B. 7.5D
- C. 0.75D
- D. 0.25D
Correct Answer & Rationale
Correct Answer: C
To find the sale price of a book that is 25% off, we first calculate the discount amount, which is 25% of the original price D. This can be expressed as 0.25D. The sale price is then the original price minus the discount, or D - 0.25D, which simplifies to 0.75D. Option A (D - 25) incorrectly subtracts a fixed dollar amount rather than a percentage, making it irrelevant to the problem. Option B (7.5D) mistakenly applies the percentage in a way that inflates the price instead of reducing it. Option D (0.25D) represents only the discount amount, not the sale price. Thus, 0.75D accurately reflects the sale price after applying the discount.
To find the sale price of a book that is 25% off, we first calculate the discount amount, which is 25% of the original price D. This can be expressed as 0.25D. The sale price is then the original price minus the discount, or D - 0.25D, which simplifies to 0.75D. Option A (D - 25) incorrectly subtracts a fixed dollar amount rather than a percentage, making it irrelevant to the problem. Option B (7.5D) mistakenly applies the percentage in a way that inflates the price instead of reducing it. Option D (0.25D) represents only the discount amount, not the sale price. Thus, 0.75D accurately reflects the sale price after applying the discount.
If 22,1/3% of a number n is 938, then n must be?
- A. 281,400
- B. 42,000
- C. 4,960
- D. 4,200
Correct Answer & Rationale
Correct Answer: D
To find the number \( n \), we start by converting \( 22 \frac{1}{3} \% \) to a decimal. This percentage equals \( \frac{67}{3} \% \), or \( \frac{67}{300} \) in decimal form. Setting up the equation \( \frac{67}{300} n = 938 \) allows us to solve for \( n \). Multiplying both sides by \( \frac{300}{67} \) gives \( n = 938 \times \frac{300}{67} = 4,200 \). Option A (281,400) is too high, as it would imply a much larger percentage. Option B (42,000) miscalculates the percentage relation. Option C (4,960) is incorrect, as it does not satisfy the equation derived from the percentage calculation.
To find the number \( n \), we start by converting \( 22 \frac{1}{3} \% \) to a decimal. This percentage equals \( \frac{67}{3} \% \), or \( \frac{67}{300} \) in decimal form. Setting up the equation \( \frac{67}{300} n = 938 \) allows us to solve for \( n \). Multiplying both sides by \( \frac{300}{67} \) gives \( n = 938 \times \frac{300}{67} = 4,200 \). Option A (281,400) is too high, as it would imply a much larger percentage. Option B (42,000) miscalculates the percentage relation. Option C (4,960) is incorrect, as it does not satisfy the equation derived from the percentage calculation.
If 32% of n is 20.8, what is n?
- A. 64
- B. 65
- C. 66
- D. 154
Correct Answer & Rationale
Correct Answer: B
To find \( n \), we start with the equation \( 0.32n = 20.8 \). By dividing both sides by 0.32, we calculate \( n = \frac{20.8}{0.32} \), which simplifies to 65. Option A (64) is incorrect; it underestimates \( n \) by miscalculating the percentage. Option C (66) slightly overestimates \( n \), failing to accurately reflect the relationship between the percentage and the total. Option D (154) is far too high, indicating a misunderstanding of the percentage calculation. Thus, 65 is the only value that satisfies the equation.
To find \( n \), we start with the equation \( 0.32n = 20.8 \). By dividing both sides by 0.32, we calculate \( n = \frac{20.8}{0.32} \), which simplifies to 65. Option A (64) is incorrect; it underestimates \( n \) by miscalculating the percentage. Option C (66) slightly overestimates \( n \), failing to accurately reflect the relationship between the percentage and the total. Option D (154) is far too high, indicating a misunderstanding of the percentage calculation. Thus, 65 is the only value that satisfies the equation.