 Hello and welcome to the session. Let us understand the following question today. Find the sum of the odd numbers between 0 and 50. Now let us write the solution. Odd numbers from 0 to 50 are 1357911 and so on till 49. So there will be 25 odd numbers between 0 and 50. Thus AP is 13579 so on till 49. Here a is equal to 1, d is equal to 3 minus 1 which is equal to 2 and n is equal to 25. Now let us find the sum. Sn is equal to n by 2 multiplied by 2a plus n minus 1d and we have to find s25. Now substituting the value of a, d and n we get 25 by 2 multiplied by 2 into 1 plus 25 minus 1 multiplied by 2 which is equal to 25 by 2 multiplied by 2 plus 24 into 2 which is equal to 25 by 2 multiplied by 2 plus 48 which is equal to 25 by 2 multiplied by 50. Now 50 get cancels by 2 and we get 25 which is equal to 25 into 25 which is equal to 625. Hence the required sum is 625. I hope you understood the question. Bye and have a nice day.