Again just to make sure I understand what I'm doing:

What is the sum of the numbers in row 15 (i.e. n=15) of Pascal's triangle?

(Answer this without computing row 15.)

$\displaystyle 2^n = \sum_{k=0}^{n}\left({n\atop k}\right)$ for all n >= 0.

So the answer would be $\displaystyle 2^{15}$ correct?