Question

One needs to recognize that averages and mixtures are effectively two sides of the same coin. This question is designed to drive home that point.

Answer 1

Let average in class C = x. Average of class B = x +16. Average of class A = y

y = 2 + 20y+30(x+16)+50x10020y+30(x+16)+50x100

(y - 2) * 10 = 2y + 3x + 48 + 5x

10y - 20 = 2y + 8x + 48

8y - 8x = 68

y - x = 8.5. This is the difference between average of class A and class C.

The question is "This question is designed to drive home that point."

Hence, the answer is "This is the difference between average of class A and class C.".