Question

in a set of five distinct positive integers, the average of the two smallest integers is 2, the average of the three smallest integers is 3, the average of the four smallest integers is 4, and the average of all five integers is 5. What is the largest integer in the set?
A. 9
B. 10
C. 11
D. 12
E. 13

Answer 1

May be 12 is correct answer..

Answer 2

Average of the 2 smallest = 2

Sum of the 2 smallest = 2 x 2 = 4

.

Average of the 3 smallest = 3

Sum of the 3 smallest = 3 x 3 = 9

.

Third number = 9 - 4 = 5

.

Average of the 4 smallest = 4

Sum of the 4 smallest = 4 x 4 = 16

.

fourth number = 16 - 9 = 5

.

Average of the 5 numbers = 5

Sum of the 5 numbers = 5 x 5 = 25

.

Fifth number = 25 - 16 = 9

.

Summary:

1st and 2nd number = sum of 4

3rd number = 5

4th number = 5

5th number = 9

.

Answer : The largest number in the set is 9.