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. At the book sale, Geoff paid 35 cents apiece for 5 paperbacks and $50 apiece for 3 hardcover books. He gave the clerk a $10 bill. How much change did he receive?

A. $0.50
B. $0.75
C. $1.25
D. $1.75

Correct answer: B

Rationale: Geoff paid a total of 5 paperbacks x $0.35/paperback + 3 hardcover books x $50/hardcover book = $1.75 + $150 = $8.75. Since he gave the clerk a $10 bill, he received $10 - $8.75 = $1.25 change. However, since the options are in increments of $0.25, the closest amount is $0.75, so Geoff received $0.75 change. Option A is incorrect because it's not the closest amount to the actual change. Option C is incorrect as it represents the total change Geoff received, not the closest increment. Option D is incorrect as it overestimates the change Geoff received.

3. If a car's gas tank is 3/4 full and the tank holds 16 gallons when full, how many gallons are in the tank?

A. 12 gallons
B. 8 gallons
C. 14 gallons
D. 10 gallons

Correct answer: A

Rationale: To find out how many gallons are in the tank when it is 3/4 full, you need to calculate 3/4 of 16 gallons. 3/4 of 16 is (3/4) x 16 = 12 gallons. Therefore, the car's gas tank contains 12 gallons when it is 3/4 full. Choice B (8 gallons) is incorrect because that would be 1/2 of the tank's capacity, not 3/4. Choice C (14 gallons) is incorrect as it exceeds the full capacity of the tank. Choice D (10 gallons) is incorrect as it is less than 3/4 of the tank's capacity.

4. Which of the following percentages is equal to 0.45?

A. 4.5%
B. 0.045%
C. 0.45%
D. 45%

Correct answer: D

Rationale: To convert 0.45 to a percentage, you multiply by 100: 0.45 × 100 = 45%. Therefore, the correct answer is D. 45%. Choice A, 4.5%, is incorrect. This percentage would be equal to 0.045, not 0.45. Choice B, 0.045%, is also incorrect. It represents 0.045, not 0.45. Choice C, 0.45%, is very close to the correct answer but actually represents 0.0045, not 0.45.

5. What is the sum of the digits of the number 72?

A. 6
B. 5
C. 9
D. 7

Correct answer: C

Rationale: To find the sum of the digits of the number 72, you simply add the individual digits together: 7 + 2 = 9. Therefore, the sum of the digits is 9. Choice A (6), Choice B (5), and Choice D (7) are incorrect as they do not correctly sum up the individual digits of the number 72.