Time Speed And Distance Questions

A and B are participants in a 1,800 m circular race. A is running at a speed of 24 km/h and B is running at a speed of 15 km/h. If both start from the same point and at the same time and run in the same direction, find the time when they will meet again. (up to two decimal points)

In a race of 400 m, Bhim gave Saral a head start of 20 m at the start of the race. Saral took 48 seconds to complete the race. What was the speed (in m/s) of Bhim if Saral defeated Bhim by a margin of 2 seconds?

A car covers $20\text{km}$ in the first quarter of an hour, $25\text{km}$ in the second quarter of that hour and $15\text{km}$ in the third quarter. The average speed of the car (in $\text{km/h}$) over the entire journey is:

A thief running at $7\text{km/h}$ is chased by a policeman whose speed is $12\text{km/h}$. If the thief is $280\text{m}$ ahead of the policeman, then the time required for the policeman to catch the thief will be:

A man wishes to cover a distance of $1\text{km}$ in river water. In still water he takes 12 minutes to cover it, but in the flowing river he takes 13 minutes. The speed of the flowing water of the river is:

A train crosses a $1000\text{ m}$ long bridge in $52\text{ seconds}$ and another $700\text{ m}$ long bridge in $40\text{ seconds}$. Assuming the train is running at a uniform speed, what is the speed (in km/h) of the train?