\begin{gather*} P(\text{5th as first}) = P(\text{LLLLA}) \\ = \frac{13 \cdot 12 \cdot 11 \cdot 10 \cdot 2}{15 \cdot 14 \cdot 13 \cdot 12 \cdot 11} = \frac{20}{15 \cdot 14} \end{gather*}