Please help me with this!!!

Determine if the following series converge or diverge.

a) the sum from n=1 to infinity of [n/3n+1]^2n

b) the sum from n=2 to infinity of [1/(n(ln)^1/2)]

I don't know what test to use with this series (comparison, ratio, integral etc)?

thank you for your help(Nod)