Question

What is the sum of an infinite geometric series if the first term is 156 and the common ratio is 2⁄3?

A. 260
B. 468
C. 208
D. 234

Answer 1

B. 468

Explanation:

We have

`a_1=156,\ r=(2)/(3)`

If |r| < 1, then the formula of a sum of an infinite geometric sequence is:

`S=(a_1)/(1-r)`

Substitute:

`S=(156)/(1-(2)/(3))=(156)/((1)/(3))=156\cdot(3)/(1)=468`