Which of the following series converge?

Question

A. 1 + 1/2^2 + 1/3^2 + ... + 1/n^2 + ...

B. 1 + 1/2 + 1/3 + ... + 1/n + ...

C. 1 - 1/3 + 1/3^2 - ... + ((-1)^(n+1))/(3^(n-1)) + ...

I think A and C are the answer.

Answer 1

A does, since ∑1/n^p converges for p>1
B does not -- the Harmonic Series
C does, since ∑1/3^n is just a geometric series with r<1

you are correct