Find the mean of the first ten natural numbers.

Find the mean of the first twenty natural numbers.

Find the sum of : the first n natural numbers

Find the mean of first ‘n’ natural numbers.

Find the sum of : the first 120 natural numbers

The simple and weighted arithmetic mean of the first n natural numbers, the weights being the corresponding numbers is

The mean of first ten odd natural numbers is

Find the median of first 5 natural numbers.

Find the sum of : the first 1000 natural numbers

Find the mean of the first five prime numbers.