Question

Find the sum of the first 33 terms of the following series, to the nearest integer. 13 , 22 , 31 , . . . 13,22,31,...

Answer 1

5,181

Explanation:

The arithmetic sequence has a common difference d = 9 which is the difference between successive terms

The sum of the first n terms of an arithmetic sequence is given by

`S_n = (n(a_1 + a_n))/(2)`

The nth term of an arithmetic sequence is given by
aₙ = a₁ + d(n - 1)

where a₁ = first term

In this particular sequence, a₁ = 13 and d = 9

Therefore
a₃₃ = 13 + 9(33-1)
= 13 + 9(32)

= 13 + 288

= 301

Therefore