**CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 17**

**17. Find the 20th term from the last term of the AP: 3, 8, 13, ...., 253.**

**Solution:**

We want to find 20th term from the last term of given AP. So, lets write given AP in this way: **253, ..., 13, 8, 3.**

First term = a = 253

Common Difference = d= 8 - 13 = -5

**Using formula** , to find nth term of arithmetic progression,** we can say that**

**Therefore, the 20th term from the last term of given AP is 158.**