The average of nine numbers is 7. If the average of six of the numbers is 8, then the average of the remaining numbers is:

5

We know that,

Average = Sum of observations / Total number of observations

The average of nine numbers is 7

So, the sum of numbers = 7 × 9 = 63

The average of six of the numbers is 8

So, the sum of numbers = 8 × 6 = 48

Sum of remaining ( 9 - 6 = 3) numbers = 63 - 48 = 15

Average of remaining 3 = 15/3 = 5