Choose the best answer. If necessary, use the paper you were given.
The number p is obtained by moving the decimal point 2 places to the left in the positive number n. The number s is obtained by moving the decimal point 1 place to the right in the number n. The number p + s how many times n?
- A. 1.01
- B. 10.001
- C. 10.01
- D. 10.1
Correct Answer & Rationale
Correct Answer: C
When the decimal point in \( n \) is moved 2 places to the left, \( p \) becomes \( \frac{n}{100} \). Moving the decimal point 1 place to the right gives \( s \) as \( 10n \). Therefore, \( p + s = \frac{n}{100} + 10n \). To combine these, convert \( 10n \) to a fraction: \( 10n = \frac{1000n}{100} \). Thus, \( p + s = \frac{n}{100} + \frac{1000n}{100} = \frac{1001n}{100} \). This simplifies to \( 10.01n \). Option A (1.01) is too low, as it does not account for the large contribution from \( s \). Option B (10.001) and D (10.1) are also incorrect; they either underestimate or overestimate the sum of \( p \) and \( s \). Thus, the correct answer, \( 10.01 \), accurately reflects the relationship between \( p + s \) and \( n \).
When the decimal point in \( n \) is moved 2 places to the left, \( p \) becomes \( \frac{n}{100} \). Moving the decimal point 1 place to the right gives \( s \) as \( 10n \). Therefore, \( p + s = \frac{n}{100} + 10n \). To combine these, convert \( 10n \) to a fraction: \( 10n = \frac{1000n}{100} \). Thus, \( p + s = \frac{n}{100} + \frac{1000n}{100} = \frac{1001n}{100} \). This simplifies to \( 10.01n \). Option A (1.01) is too low, as it does not account for the large contribution from \( s \). Option B (10.001) and D (10.1) are also incorrect; they either underestimate or overestimate the sum of \( p \) and \( s \). Thus, the correct answer, \( 10.01 \), accurately reflects the relationship between \( p + s \) and \( n \).
Other Related Questions
1,500 / (15 + 5) =
- A. 75
- B. 130
- C. 315
- D. 400
Correct Answer & Rationale
Correct Answer: A
To solve the expression 1,500 / (15 + 5), first calculate the sum in the parentheses: 15 + 5 equals 20. Next, divide 1,500 by 20. Performing the division gives 1,500 รท 20 = 75, confirming option A as the correct answer. Option B (130) results from an incorrect division or miscalculation. Option C (315) likely stems from misunderstanding the order of operations, possibly miscalculating the sum before division. Option D (400) may arise from mistakenly multiplying instead of dividing. Understanding the correct order of operations is crucial for accurate calculations.
To solve the expression 1,500 / (15 + 5), first calculate the sum in the parentheses: 15 + 5 equals 20. Next, divide 1,500 by 20. Performing the division gives 1,500 รท 20 = 75, confirming option A as the correct answer. Option B (130) results from an incorrect division or miscalculation. Option C (315) likely stems from misunderstanding the order of operations, possibly miscalculating the sum before division. Option D (400) may arise from mistakenly multiplying instead of dividing. Understanding the correct order of operations is crucial for accurate calculations.
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, multiply the number of books Jerry has (15) by 5, since Marisol has 5 times as many. This calculation yields 15 x 5 = 75. Option A (10) is incorrect as it underestimates the multiplication factor. Option B (20) also miscalculates, suggesting a much lower total. Option D (225) overestimates the number of books, resulting from an incorrect multiplication. Thus, the only accurate answer is 75, reflecting Marisol's total based on Jerry's count.
To determine how many books Marisol has, multiply the number of books Jerry has (15) by 5, since Marisol has 5 times as many. This calculation yields 15 x 5 = 75. Option A (10) is incorrect as it underestimates the multiplication factor. Option B (20) also miscalculates, suggesting a much lower total. Option D (225) overestimates the number of books, resulting from an incorrect multiplication. Thus, the only accurate answer is 75, reflecting Marisol's total based on Jerry's count.
Last year Joan's salary was $18,000. If she receives a $900 raise for this year, what percent of last year's salary is her raise?
- A. 2%
- B. 5%
- C. 20%
- D. 50%
Correct Answer & Rationale
Correct Answer: B
To find the percentage of last year's salary that Joan's raise represents, divide the raise amount by last year's salary and then multiply by 100. Here, $900 (raise) divided by $18,000 (last year's salary) equals 0.05. Multiplying by 100 gives 5%, which is the correct answer. Option A (2%) miscalculates the raise as a smaller fraction of the salary. Option C (20%) incorrectly interprets the raise as a larger proportion, perhaps confusing it with a different calculation. Option D (50%) vastly overestimates the raise, suggesting it is half of last year's salary, which is not accurate.
To find the percentage of last year's salary that Joan's raise represents, divide the raise amount by last year's salary and then multiply by 100. Here, $900 (raise) divided by $18,000 (last year's salary) equals 0.05. Multiplying by 100 gives 5%, which is the correct answer. Option A (2%) miscalculates the raise as a smaller fraction of the salary. Option C (20%) incorrectly interprets the raise as a larger proportion, perhaps confusing it with a different calculation. Option D (50%) vastly overestimates the raise, suggesting it is half of last year's salary, which is not accurate.
3(1/2) * 2(1/3) =
- A. 8(1/6)
- B. 7(5/6)
- C. 6(1/6)
- D. 5(5/6)
Correct Answer & Rationale
Correct Answer: A
To solve 3(1/2) * 2(1/3), first convert the mixed numbers to improper fractions: 3(1/2) becomes 7/2 and 2(1/3) becomes 7/3. Multiplying these fractions yields (7/2) * (7/3) = 49/6. Converting 49/6 back to a mixed number gives 8(1/6). Option B, 7(5/6), results from incorrect multiplication. Option C, 6(1/6), miscalculates the product as well. Option D, 5(5/6), reflects a misunderstanding of fraction multiplication. The proper method confirms that 8(1/6) is indeed the accurate result.
To solve 3(1/2) * 2(1/3), first convert the mixed numbers to improper fractions: 3(1/2) becomes 7/2 and 2(1/3) becomes 7/3. Multiplying these fractions yields (7/2) * (7/3) = 49/6. Converting 49/6 back to a mixed number gives 8(1/6). Option B, 7(5/6), results from incorrect multiplication. Option C, 6(1/6), miscalculates the product as well. Option D, 5(5/6), reflects a misunderstanding of fraction multiplication. The proper method confirms that 8(1/6) is indeed the accurate result.