What is the sum of the cubes of first n natural numbers?

The sum of first n odd natural number is

Find the variance of first n natural numbers.

Find the sum of first n even natural numbers.

Find the sum of first n terms of even natural numbers .

Chosse the correct one The sum of first 100 natural number is

The sum of the square of two consecutive natural number is 313,find the numbers.

If S_1.S_2,S_3 are the sum of first n natural numbers,their squares and their cubes respectively,Show that : 9S_2^2=S_3(1+8S_1) .

The sum of the square of two consecutive even natural number is 340,find the numbers.

Find the standard deviation of first 10 natural numbers.

Find the sum of all three digit natural number which is divisible by 13.