1) That's no good. n/(n+1) < 1 Why would you want to make it even bigger? It's already too big, just because it is an integral value and not a discrete sum. Of course, that IS an upper bound, but you may wish to find a smaller one.

2) Why would you not start at 11? You already used 10.

3) There are various ways to find the value of an integral. Don't give up because you don't see the anti-derivative. Starting at 11, I get around 4.739 x 10^(-6)