Question

In a science class, 40% of the students received a grade of A, 30% received a grade of B, and 20% received a grade of C on a project. The others fell short of a passing grade. a. If 12 students received an A, how many students were in the science class? b. How many students received a failing grade?

Answer 1

30 students are in the science class and 3 students recieved a failing grade.

Answer 2

30, 3

Explanation:

a. Let's call the total students x. If 40% x = 12, 0.4x = 12, x = 12/0.4 = 30 students.

b. We know that 100 - 40 - 30 - 20 = 10% of all students failed. This is 10% * 30 = 0.1 * 30 = 3 students.