 Hello and welcome to this session. I am Ashrama and I am going to help you with the following problem. Find the sum of the following AP. We have 2, 7, 12, so on till 2, 10 terms. Now before writing the solution let us look at the key idea. Key idea of this problem is Sn is equal to n by 2 multiplied by 2a plus n minus 1b where a is the first term, d is the common difference and then the number of terms. So now let us write the solution. Given AP is 2, 7, 12, so on till 10 terms. Now here a is equal to 2, d is equal to the common difference that is 7 minus 2 which is equal to 5 and number of terms that is n is equal to 10. So applying the formula with the sculpting key idea we get that is Sn is equal to n by 2 2a plus n minus 1d which is equal to n is 10 by 2 2 multiplied by 2 plus 10 minus 1 multiplied by 5. This is equal to this cuts by 5, so 5 multiplied by 4 plus 9 multiplied by 5 which is equal to 5 multiplied by 4 plus 45 which is equal to 5 multiplied by 49 which is equal to 245 therefore required sum is 245. I hope you understood this problem bye and have a nice day.