Solution:

Provided here,
The common difference, d = 7

22^nd term, a₂₂ = 149

The sum of the first 22 term, S₂₂ = ?

Using the nth term formula,

a_n = a+(n−1)d

a₂₂ = a+(22−1)d

149 = a+21×7

149 = a+147

a = 2 = First term

The sum of n terms,

S_n = n/2(a+a_n)

S₂₂ = 22/2 (2+149)

= 11×151

= 1661