if kevin can wash 30 cars in 15 minutes how many minutes will it take him to wash 100 cars

HESI A2

Math HESI A2 Practice Test

1. 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.

2. What is the result of adding 1/4 + 3/8?

A. 5/8
B. 7/12
C. 2/3
D. 1/2

Correct answer: A

Rationale: To add fractions with different denominators, find a common denominator. In this case, the common denominator of 4 and 8 is 8. Convert 1/4 to 2/8, then add it to 3/8. The sum is 5/8. Choice B (7/12) is incorrect as it is the result of adding 1/3 + 1/4. Choice C (2/3) is incorrect as it is the result of adding 3/8 + 1/4. Choice D (1/2) is incorrect as it is the result of adding 1/4 + 1/4.

3. What percent of 36 is 9?

A. 25%
B. 20%
C. 15%
D. 10%

Correct answer: D

Rationale: To find out what percent 9 is of 36, divide 9 by 36 and multiply by 100 to convert it to a percentage. So, (9/36) * 100 = 25%. This indicates that 9 is 25% of 36, not 10%. Choice A, 25%, is the result of calculating what percent 36 is of 9, not the other way around. Choices B and C are incorrect as they do not align with the calculated percentage.

4. Divide and simplify: 4⅛ ÷ 1½ =

A. 4½
B. 4¼
C. 2¾
D. 2¼

Correct answer: C

Rationale: To divide mixed numbers, we first convert them to improper fractions. Converting 4⅛ to an improper fraction gives us 33/8, and converting 1½ gives us 3/2. Dividing 33/8 by 3/2, we multiply the first fraction by the reciprocal of the second. This gives us (33/8) / (3/2) = (33/8) * (2/3) = 66/24 = 11/4, which simplifies to 2¾. Therefore, the correct answer is 2¾. Choices A, B, and D are incorrect as they do not represent the correct result of dividing 4⅛ by 1½.

5. What is the result of adding 6 3/4 + 8 1/6?

A. 14 11/12
B. 12 3/4
C. 12 3/24
D. 14 2/5

Correct answer: A

Rationale: To add mixed numbers, convert them to improper fractions: 6 3/4 = 27/4 and 8 1/6 = 49/6. Then, add the fractions to get 27/4 + 49/6 = 162/24 + 98/24 = 260/24 = 21 20/24 = 21 10/12 = 21 5/6 = 14 11/12. Therefore, the correct answer is 14 11/12. Choice B (12 3/4) is incorrect as it does not match the correct calculation. Choice C (12 3/24) is incorrect due to the erroneous denominator in the final fraction. Choice D (14 2/5) is incorrect as it does not correspond to the correct sum of the fractions.