Find the sum of the first 100 natural numbers.

The famous mathematician associated with finding the sum of the first 100 natural numbers is

Find the sum of first 100 even natural numbers which are divisible by 5.

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.

Find the sum of first 10 even natural numbers.

Find the sum of first 15 odd natural numbers.

For some natural number 'n', the sum of the first 'n' natural numbers is 240 less than the sum of the first (n+5) natural numbers. Then n itself is the sum of how many natural numbers starting with 1.

Let S_n denote the sum of the cubes of the first n natural numbers and s_n denote the sum of the first n natural numbers. Then sum_(r=1)^n S_r/s_r is equal to

(i) Find the sum of first 200 even natural numbers. (ii) Find the sum of all numbers lying between 201 and 424 which are divisible by 5. (iii) Find the sum of all numbers from 1 to 200 which are divisible by either 2 or 3.

let S_(n) denote the sum of the cubes of the first n natural numbers and s_(n) denote the sum of the first n natural numbers , then sum_(r=1)^(n)(S_(r))/(s_(r)) equals to