An infinite geometric series converges to a finite sum

MATHEMATICS · Single correct · A Level · Mathematics · Sequences and series · Sequences and series

Problem

An infinite geometric series converges to a finite sum. Which one of the following conditions on the common ratio

r

is always true? (a)

|r|\le 1

(b)

|r|>1

(c)

|r|<1

(d)

r<1