if 30 of a given number is 18 what is the full number

HESI A2

HESI A2 Practice Test Math

1. If 30% of a given number is 18, what is the full number?

A. 60
B. 30
C. 40
D. 45

Correct answer: A

Rationale: If 30% of a number is 18, you can find the full number by dividing 18 by 0.30 (the decimal equivalent of 30%). This calculation results in 60. Therefore, the full number is 60. Choice B (30) is the result if 30% of the number itself was calculated, not the full number. Choices C (40) and D (45) are incorrect and do not align with the given information.

2. If Kevin can wash 30 cars in 15 minutes, how many minutes will it take him to wash 100 cars?

A. 50 minutes
B. 55 minutes
C. 30 minutes
D. 45 minutes

Correct answer: A

Rationale: To find out how many minutes Kevin will take to wash 100 cars, set up a proportion: 30 cars is to 15 minutes as 100 cars is to x minutes. Cross multiplying gives 30x = 1500. Solving for x, x = 1500 / 30 = 50. Therefore, it will take Kevin 50 minutes to wash 100 cars. Choice A is correct. Choice B, C, and D are incorrect as they do not correctly calculate the time needed based on the given information.

3. After putting ⅓ aside for her share of rent and utilities and spending $75 on groceries, what is left from her weekly paycheck?

A. $150
B. $214.86
C. $204.26
D. $192.76

Correct answer: A

Rationale: If she puts aside 1/3 of her paycheck for rent and utilities, this means she spends 3 portions in total. So, 1 portion represents 1/3 of the paycheck. Since she spends $75 on groceries, it leaves 2 portions. The total amount of 3 portions is the paycheck. To find out one portion, divide the total paycheck by 3: Paycheck = 3 portions. $75 is one portion. Multiply the one portion by 3 to find the total paycheck: $75 * 3 = $225. Subtract the spent amount from the weekly paycheck: $225 - $75 = $150. Therefore, the amount left from her weekly paycheck is $150. The other choices are incorrect because they do not follow the correct calculation based on the given information.

4. How many ounces are in 3 quarts?

A. 64 ounces
B. 32 ounces
C. 48 ounces
D. 96 ounces

Correct answer: D

Rationale: There are 32 ounces in a quart. Therefore, 3 quarts would be equal to 3 quarts x 32 ounces = 96 ounces. The correct answer is D. Choice A, 64 ounces, is incorrect as it miscalculates the conversion from quarts to ounces. Choice B, 32 ounces, is the conversion for 1 quart, not 3 quarts. Choice C, 48 ounces, is also an incorrect calculation, not considering the correct conversion rate.

5. Express 4/5 as a percent.

A. 20%
B. 40%
C. 50%
D. 80%

Correct answer: D

Rationale: To convert a fraction to a percentage, you multiply the fraction by 100. To express 4/5 as a percent, you perform the calculation 4/5 * 100 = 80%. Therefore, the correct answer is D, 80%. Choices A, B, and C are incorrect as they do not represent the correct conversion of 4/5 to a percentage.