Sum of the squares of the first n natural numbers exceeds their sum by 330 then find n.

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

Write the sum of first n natural numbers.

What is the sum of first 20 natural numbers?

What is the sum of first 30 natural numbers?

Sum,of the squares of three consecutive natural numbers is 110.

Form the equation:The sum of first n natural numbers is 210

Find the mean and variance of first n natural numbers.

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

Standard deviation of first n odd natural numbers is