$A$ train $100 \, m$ long takes $3 \frac{3}{5} \, s$ to cross a man walking at the rate of $6 \, km/h$ in a direction opposite to that of the train. Find the speed of the train in $km/h$.

$A, B$ and $C$ start together from the same place to walk around a circular path of length $12 \, km$. $A$ walks at the rate of $4 \, km/h$,$B$ at $3 \, km/h$,and $C$ at $\frac{3}{2} \, km/h$. They will meet together at the starting place at the end of (in $h$):

$A$ motor car completes a journey in $10 \, hrs$. It covers the first half of the distance at $21 \, km/hr$ and the second half at $24 \, km/hr$. Find the total distance in $km$.

Sound travels $330 \text{ m/s}$. If the sound of a thundercloud is heard $10 \text{ s}$ after the flash,the distance of the thundercloud is (in $\text{km}$):

The ratio between the speed of a train and a car is $16: 15$. Also,a bus covered a distance of $480 \, km$ in $8 \, hours$. The speed of the bus is $\frac{3}{4}$ the speed of the train. How much distance will the car cover in $6 \, hours$? (in $km$)

$A$ train $180 \, m$ long is running at a speed of $90 \, km/h$. How long will it take to pass a post? (in $sec$)