The total number of students in section A and B of a class is 110. The number of students in section A is 10 more than that of section B. The average score of the students in B, in a test, is 20% more than that of students in A. If the average score of all the students in the class is 72, then what is the average score of the students in A?

Answer: Option A

Solution

Answer: Option A

Solution:

A + B = 110
x + 10 + x = 110
x = 50
A = 60
B = 50

$$\frac{6\text{x}-72}{72-5\text{x}}=\frac{6}{5}$$
(x - 12) × 5 = 72 - 5x
5x - 60 = 72 - 5x
10x = 132
A = 5x = 66