 Hi and welcome to the session. I am Shashi. Let us do one question. Question is, find the 20th term from the last term of the AP, 3A, 13 till 253. First upon, let us understand the key idea to solve the given question. If L is the last term of the AP, then the N-th term from the end is the N-th term of an AP whose first term is L and the common difference is minus 10. Generally, we know the general formula of N-th term is equal to A plus N minus 1 multiplied by D. So, L-th term from the end is equal to last term as last term will become the first term. So, we will write last term plus N minus 1 multiplied by minus E. D will get replaced by minus D. So, we get the formula for L-th term from the end is equal to L minus N minus 1 multiplied by D. Let us now start with the solution. We know given AP in the question is 3A, 13 till 253. Now, clearly last term of the AP that is L is equal to 253, right? Now, common difference that is D is equal to 5. Now, we know the formula for N-th term from the end is equal to L minus N minus 1 multiplied by D as we have already understood in the P-idea. Now, L is equal to 253 and D is equal to 5. So, we get N-th term from the end is equal to 253 minus N minus 1 multiplied by 5. Now, we have to find that 20th term from the end. So, we can write 20th term the end is equal to 253 minus 20 minus 1 multiplied by 5. Now, this is equal to 253 minus 19 multiplied by 5 which is equal to 253 minus 95 which is further equal to 158. So, we can write 20th term from the end is equal to 158. So, 20th term from the last term is 150 H. This is our final answer. This completes the session. Hope you understood the session. Take care and goodbye.