Question

The average of three numbers is 36 .The average of two of these numbers is 48 . What is the third number ?

Answer 1

the average of 3 numbers is 36 so the sum of those numbers is 36×3 = 108
and avarage of 2 of them is 48 so sum of those is 96
hense the 3rd one is 108-96=12

Answer 2

Let the third number be x.

Given that the average of three numbers is 36 and average of two of these numbers is 48.

48 + 48 + x/3 = 36.

96 + x/3 = 36

96 + x = 108

x = 108 - 96

x = 12.

Verification:

48 + 48 + 12/3

108/3

36.

Therefore the third number = 12.

Hope this helps!