Which one of the following infinite series is convergent?

MATHEMATICS · Single correct · AP · Calculus BC · Infinite Sequences and Series · Infinite Sequences and Series

Problem

Which one of the following infinite series is convergent? (a)

7 + 7 + 7 + \dots

(b)

1 + \dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+\dots

(c)

8 + 4 + 2 + 1 + \dots

(d)

5 - 10 + 20 - 40 + \dots