A train crosses a pole in $12$ seconds and a bridge of length $170$ meters in $36 \mathrm{~sec}$. The speed of the train is ________
- $30.75 \mathrm{~km} / \mathrm{h}$
- $32.45 \mathrm{~km} / \mathrm{h}$
- $25.5 \mathrm{~km} / \mathrm{h}$
- $10.8$ $\mathrm{~km} / \mathrm{h}$