Find the average of first 20 consecutive natural numbers.

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

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

Let five odd consecutive natural numbers be P, Q, R, S and T. What is their average?

The average of three consecutive odd numbers is 43. What is the average of the smallest and largest?

If x is the average of 1², 2², 3², ..., 10² and y is the average of first 10 even natural numbers, then y is what percent of x − y?