# Is there a short method?

Discrete Mathematics Level 5

$\sum _{ r=1 }^{ 15 }{ { \left( -1 \right) }^{ r+1 }\left( \begin{matrix} 15 \\ r \end{matrix} \right) \left( \begin{matrix} 17r \\ 15 \end{matrix} \right) } =A$

Find the second last digit of $$A$$.

×