Let $p$ be a prime number. The order of a $p$-Sylow subgroup of the group $GL_{50}(\mathbb{F}_p)$ of invertible $50×50$ matrices with entries from finite field $\mathbb{F}_p$ equals:
$p^{50}$
$p^{125}$
$p^{1250}$
$p^{1225}$
I am completely stuck on it.can anyone help me please.