Question

What is the sum of the arithmetic sequence 3, 9, 15..., if there are 34 terms?A) 2,467B) 2,684C) 3,072D) 3,468

Answer 1

Given,

The arithmetic sequence is 3,9, 15, ........

Required

The sum of 34 terms of the series.

Here,

The first term of the series is,

a = 3

The common difference of the series is,

d = 9 -3 = 6

The number of terms are 34

The sum of the series is calculated as,

`\begin{gathered} Sum=(n)/(2)(2a+(n-1)d) \\ =(34)/(2)(2*3+(34-1)6) \\ =17(6+33*6) \\ =3468 \end{gathered}`

Hence, the sum of the series is 3468.