Problem 3. Test the following series for convergence or divergence (2n)! nn a. b. 3n (n!)2 3n n! n=1 n=1 Problem 4. Let { an}, be a sequence such that an > 0 for every n 2 1. Assume that the series E an n=1 is convergent. Does it necessarily mean that the series [(-1)man n=1 is convergent? Justify your