The average of all prime numbers between 60 and 80 is:

If the average of m numbers is n*n and that of n numbers is m*m , then the average of m+n numbers is

The average of the first 8 numbers is 42. The average of the first 4 numbers is 40, and the average of the next 3 numbers is 44. What is the 8th number?

The sum of nine consecutive natural numbers is 2088. The average of prime numbers among these numbers is

The average of square of first 6 consecutive even numbers is:

The average of 6 numbers is 5. The first number is increased by 2, second by 4, third by 8 and so on. The average of new numbers is