An art teacher has 28 students in her first-period class and 24 students in her second-period class. If almost 30% of the students in these classes are boys, about how many boys are in her first two classes? A. 36
B. 15
C. 8
D. 7

C. 8

Explanation:
One way to solve this is to find 30% of each class, 28 and 24.

30% of 28:
28 • 0.30 = 8.4
30% of 24:
24 • 0.30 = 7.2

You can then find the average of these two numbers.

8.4 + 7.2 = 15.6
15.6 ➗ 2 = 7.8
7.8 rounds up to 8

Another way to solve is to first find the average number of people in each class.

28 + 24 = 52
52 ➗ 2 = 26

You can then find 30% of this number.

26 • 0.30 = 7.8
7.8 rounds up to 8