# Find the sum of the first 22 terms of an AP in which d = 7 and 22nd term is 149

**Solution:**

Sum of the first n terms of an AP is given by S_{n} = n/2 [2a + (n - 1) d].

Here, a is the first term, d is the common difference and n is the number of terms.

Given,

- 22nd term, l = a
_{22}=149 - Common difference, d = 7

We know that nth term of AP, an = a + (n - 1)d

a_{22} = a + (22 - 1) d

149 = a + 21 × 7

149 = a + 147

a = 2

The sum of 22 terms can be found as follows.

S_{n} = n/2 [a + l]

= 22/2 (2 +149)

= 11 × 151

= 1661

**Video Solution:**

## Find the sum of the first 22 terms of an AP in which d = 7 and 22nd term is 149

### Class 10 Maths NCERT Solutions Chapter 5 Exercise 5.3 Question 7 - Chapter 5 Exercise 5.3 Question 7:

Find the sum of the first 22 terms of an AP in which d = 7 and 22nd term is 149

The sum of the first 22 terms of an AP in which d = 7 and 22nd term is 149 is 1661