CBEST Math: Computation and Problem-Solving 4

Question 1

A school has 450 students. If 54 students are absent, what percent are absent?

Accepted Answer

12%

Answer

54/450 = 0.12 = 12%.

Question 2

What is the least common multiple (LCM) of 8 and 12?

Accepted Answer

24

Answer

The LCM of 8 and 12 is 24 because it is the smallest number divisible by both.

Question 3

A tank is 3/5 full. After adding 120 gallons, it is 4/5 full. What is the tank's total capacity?

Accepted Answer

600 gallons

Answer

120 gallons represents 4/5 − 3/5 = 1/5 of capacity, so total = 120 × 5 = 600 gallons.

Question 4

If the average of five numbers is 18, and four of the numbers are 14, 16, 20, and 22, what is the fifth number?

Accepted Answer

18

Answer

The total is 5 × 18 = 90; the sum of the four known numbers is 72; the fifth is 90 − 72 = 18.

Question 5

Which number is NOT a prime number?

Accepted Answer

51

Answer

51 = 3 × 17, so it is not prime; the others have no factors other than 1 and themselves.

CBEST - California Basic Educational Skills Test Practice Test