# How to Find the Sum of odd Numbers – Using Sum of N terms Formula of Arithmetic Series

In previous videos we learn to prove Arithmetic progression and then finding the sum. You are good in such problems too.

Now friend in this video lesson we are learning to find the sum of odd numbers by the method of sequence and series specially applying the sum of arithmetic progression formula..

Well let’s start how to find sum of odd numbers. I hope you always sit with pen and notebook.

Great ! How you are feeling now! It was quite easy right just few steps to find the sum of odd numbers between any two numbers.

Steps to find Sum of Odd Numbers

1. First write the first term and last term of odd number. The form it as a AP.

2. Apply the nth term formula of arithmetic progression on the last term.

3. By doing so (step2) we will get the value of total number of terms in that AP.

4. Now since we know first term(a), last term (l), number of terms (n), we can easily apply the sum of arithmetic progression formula to get the sum of odd numbers.

Cheers!

Well friend here I have listed few exercise related to sum of Arithmetic progression just like above. Please try to solve these all. It will really help you.

Q1. Find the sum of all odd numbers between 100 to 200. (ans = 7500)

Q2. Find the sum of all odd integers between 2 and 100 divisible by 3. (Ans = 867)

## Comments

## khan

hi bro

your A.P chapter is incomplete i think.

it doesnot contain arithmetic mean mean concept. i just some of that concept if they have

so tell me where it is

im putting link-

http://maharashtrassc.meritnation.com/cbse-math-mathematics-(algebra)/arithmatic-progressions-and-geometric-progressions/696/3914/studymaterials.html#8338