Let $p$ be a prime number . The order of a $p$-Sylow subgroup of the group $GL_{50}(F_p)$ of invertible $50\times50$ matrices with entries from the finite field $F_p$,equals which of the following
1.$p^{50}$
2.$p^{125}$
3.$p^{1250}$
4.$p^{1225}$
I think order of this group is $p^{2500}$ .A sylow p-subgroup of order $P^k$ divides order of the group but $p^{k+1}$ does not. I confused here how to apply these things .