Question

The mean of nine numbers is 12 , if one of the numbers is removed ,

the mean becomes 13 , What is the number that was removed .

Answer 1

• 4

Explanation:

Mean of 9 numbers is 12.

Total of 9 numbers:

• 9*12 = 108

Mean of 8 numbers is 13.

Total of 8 numbers:

• 8*13 = 104

Removed number:

• 108 - 104 = 4