Question #N757

The average of 5 numbers is 12. If one of the numbers is removed, the average of the remaining 4 numbers is 10. What is the value of the number that was removed?
A. 10
B. 12
C. 18
D. 20

Correct Answer is: D

The sum of the original 5 numbers is 5 * 12 = 60. The sum of the remaining 4 numbers is 4 * 10 = 40. Therefore, the number that was removed is 60 - 40 = 20.