GMAT MATH Practice Questions - Averages

April 13, 2004

The average of 5 quantities is 6. The average of 3 of them is 8. What is the average of the remaining two numbers?

(A)	4
(B)	5
(C)	3
(D)	3.5
(E)	0.5

Correct Choice (C) Answer (3)

Explanatory Answer

The average of 5 quantities is 6.
Therefore, the sum of the 5 quantities is 5 * 6 = 30.

The average of three of these 5 quantities is 8.
Therefore, the sum of these three quantities = 3 * 8 = 24

The sum of the remaining two quantities = 30 – 24 = 6.
Average of these two quantities = = 3.