Question

Find the sum of the first 36 terms of the following series, to the nearest integer.
2, 5,8,...

Answer 1

Explanation:

Comment.

You need to use the addition formula when the last term is not given. Mind you, you could find it, but it is just as easy to get the answer without it.

Givens

a1 = 2

d = 3

n = 36

Formula

Sum = n(a1 + (n - 1)* d)/2

Solution

Sum = 36(2 + (36 - 1)*3 )/2 Combine the brackets

Sum = 36 (2 + 35*3 )/2

Sum = 36(2 + 105) /2 Combine the brackets

Sum = 36 * 107/2

Sum = 3852 /2

Sum = 1926

Answer

1926