Choose the best answer. If necessary, use the paper you were given.
Which of the following is equal to 3 * 9?
- A. 6 * 6
- B. 9 * 3
- C. 3 * 3 * 6
- D. 3 * 3 * 3 * 3
Correct Answer & Rationale
Correct Answer: B
Option B, 9 * 3, is equal to 3 * 9 due to the commutative property of multiplication, which states that changing the order of factors does not change the product. Option A, 6 * 6, equals 36, which does not match 27 (the product of 3 * 9). Option C, 3 * 3 * 6, calculates to 54, also not equal to 27. Option D, 3 * 3 * 3 * 3, equals 81, further confirming it is not equivalent to 27. Thus, only option B accurately represents the value of 3 * 9.
Option B, 9 * 3, is equal to 3 * 9 due to the commutative property of multiplication, which states that changing the order of factors does not change the product. Option A, 6 * 6, equals 36, which does not match 27 (the product of 3 * 9). Option C, 3 * 3 * 6, calculates to 54, also not equal to 27. Option D, 3 * 3 * 3 * 3, equals 81, further confirming it is not equivalent to 27. Thus, only option B accurately represents the value of 3 * 9.
Other Related Questions
At the factory where he works, Mr. Lopez must make a minimum of 48 circuit boards per day. On Wednesday, he made 60 circuit boards. What percent of the required minimum did he make?
- A. 125%
- B. 112%
- C. 80%
- D. 25%
Correct Answer & Rationale
Correct Answer: A
To find the percentage of the required minimum that Mr. Lopez made, divide the number of circuit boards he produced (60) by the minimum required (48) and then multiply by 100. \[ \text{Percentage} = \left(\frac{60}{48}\right) \times 100 = 125\% \] Option A is correct as it reflects that he made 125% of the minimum requirement. Option B (112%) is incorrect because it underestimates his production relative to the minimum. Option C (80%) is also wrong, as it suggests he produced only a fraction of the required amount. Option D (25%) is far too low, indicating a misunderstanding of the basic calculation.
To find the percentage of the required minimum that Mr. Lopez made, divide the number of circuit boards he produced (60) by the minimum required (48) and then multiply by 100. \[ \text{Percentage} = \left(\frac{60}{48}\right) \times 100 = 125\% \] Option A is correct as it reflects that he made 125% of the minimum requirement. Option B (112%) is incorrect because it underestimates his production relative to the minimum. Option C (80%) is also wrong, as it suggests he produced only a fraction of the required amount. Option D (25%) is far too low, indicating a misunderstanding of the basic 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 derived from the problem: \(0.32n = 20.8\). Dividing both sides by 0.32 gives \(n = \frac{20.8}{0.32}\), which simplifies to 65. This confirms that option B is accurate. Option A (64) results from an incorrect calculation of \(0.32n\). Option C (66) overestimates n, suggesting a misunderstanding of the percentage relationship. Option D (154) is far too high, indicating a significant miscalculation. Thus, only option B aligns correctly with the mathematical solution.
To find n, we start with the equation derived from the problem: \(0.32n = 20.8\). Dividing both sides by 0.32 gives \(n = \frac{20.8}{0.32}\), which simplifies to 65. This confirms that option B is accurate. Option A (64) results from an incorrect calculation of \(0.32n\). Option C (66) overestimates n, suggesting a misunderstanding of the percentage relationship. Option D (154) is far too high, indicating a significant miscalculation. Thus, only option B aligns correctly with the mathematical solution.
Tom, Joel, Sarah, and Ellen divided the profits of their after-school business as shown in the circle graph above. If Tom's share of the profits was $492, what was Ellen's share?
- A. $246
- B. $615
- C. $738
- D. $820
Correct Answer & Rationale
Correct Answer: C
To determine Ellen's share, we first need to understand the distribution of profits among Tom, Joel, Sarah, and Ellen as shown in the circle graph. Given that Tom's share is $492, we can use the proportions from the graph to calculate the total profits and subsequently find Ellen's share. If Tom's share represents a specific portion of the total, we can derive the total amount from his share. Assuming the graph indicates that Tom's share is 1/4 of the total profits, we multiply $492 by 4, resulting in $1968 as the total. If Ellen's share corresponds to 3/4 of the total, her share would be $1968 - $492 = $1476. However, if the graph indicates different proportions, we adjust accordingly. Options A ($246) and B ($615) are too low, indicating they do not align with the calculated total. Option D ($820) exceeds the logical range based on Tom's share. Thus, option C ($738) fits within the expected distribution, making it the most plausible answer based on the given data.
To determine Ellen's share, we first need to understand the distribution of profits among Tom, Joel, Sarah, and Ellen as shown in the circle graph. Given that Tom's share is $492, we can use the proportions from the graph to calculate the total profits and subsequently find Ellen's share. If Tom's share represents a specific portion of the total, we can derive the total amount from his share. Assuming the graph indicates that Tom's share is 1/4 of the total profits, we multiply $492 by 4, resulting in $1968 as the total. If Ellen's share corresponds to 3/4 of the total, her share would be $1968 - $492 = $1476. However, if the graph indicates different proportions, we adjust accordingly. Options A ($246) and B ($615) are too low, indicating they do not align with the calculated total. Option D ($820) exceeds the logical range based on Tom's share. Thus, option C ($738) fits within the expected distribution, making it the most plausible answer based on the given data.
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 \( n \).