Ok, first I am face with the series from 1 to infinity of (n!)e^(-n) I used the ratio test and came out with lim-->infinity of (n+1)e through cancellation. I don't see how the series is divergent, can anyone explain? Secondly, for the series from 1 to infinity of 11/n(n+2) -- > I can determine that it is convergent using the limit test with 1/n to show that the limit is a number > 0 so both diverge. But how can I get the sum?????? Someone pointed out that this is a telescoping series. But how can I know this? and how do I get the partial fractions. This will help me prepare for my coming exam. THANK YOU.