Question

What is the sum of an infinite geometric series if the first term is 8 and the common ratio is 1⁄2?

A. 8
B. 16
C. 32
D. 4

Answer 1

B. 16

Explanation:

The sum is given in terms of the first term a1 and the common ratio r as ...

S = a1·1/(1-r)

Substituting the given values and doing the arithmetic, we find ...

S = 8/(1 -1/2) = 16

The sum of the series is 16.