Question

A class has 45 students. Each student has either 5 dollars or 2 dollars. Which Which situation results in the class having an average of 3 dollars per student

Answer 1

Explanation:

an average of $3 per student would mean

sum(all students $) / 45 = 3

sum(all students $) = 3×45 = 135

x students have $5.

therefore (45-x) students have $2.

5x + 2(45-x) = 135

5x + 90 - 2x = 135

3x = 45

x = 15

so, 15 students have $5, and 45-15 = 30 students have $2.