**CBSE NCERT Solutions Chapter 5 Arithmetic Progressions Exercise 5.2 Question 13**

**13. How many three digit numbers are divisible by 7?**

**Solution:**

We have AP starting from because it is the first three digit number divisible by .

AP will end at because it is the last three digit number divisible by .

Therefore, we have AP of the form

Let is the nth term of AP. We need to find n here.

First term = a = 105

Common difference = d = 112 - 105 = 7

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

**It means is the 128th term of AP. Therefore, there are terms in AP. In other words, we can also say that there are 128 three digit numbers divisible by 7.**