Find the sum of first 100 natural numbers.

Find the sum of first n natural numbers.

The sum of first 30 natural numbers is:

The mean of first 10 natural numbers is

Find the mean of first five natural numbers.

Statement 1 The difference between the sum of the first 100 even natural numbers and the sum of the first 100 odd natural numbers is 100. Statement 2 The difference between the sum opf the first n even natural numbers and sum of the first n odd natural numbers is n.

If the sum of first n even natural numbers is equal to k times the sum of first n odd natural numbers, then k is equal to:

Find the arithmetic mean of first 8 natural numbers.

Find the sum of of the products of first n natural numbers, taken two at a time .

Find the sum of all natural numbers lying between 100 and 1000, which are multiples of 5.