A train 400 m long passes a pole in 20 seconds. What is the speed of the train?

A man rides his vehicle at the rate of 36 km/hr but stops for 12 minutes, to change parts at the end of every 14^th  km,what will be the timed taken to cover a distance of 90 km?

A policeman spotted a thief 200 meter apart. The thief starts running at the speed of 10km/hr. and e policeman chases him at the respectively 11 km/hr. Then find the distance between them after 6 minute -

Ajay covers distance by car driving at 60 kmph and returns back to the starting point riding on a  scooter at 45 kmph. What is his average speed?

The ratio of the speeds of the two airplanes is 7:15. If the first airplane covers a distance of 1050 km in 3 hours, what is the speed of the second airplane?

Vipin swims in a 72 meter long pond. He travels 144 meters in one minute by swimming from one end to the other and coming back the same way, find his average speed.

Two trains start from P and Q respectively and travel towards each other at a speed of 50 km/hour and 40 km/hour respectively. By the time they met the first train had travelled 100 km more than the second. Find the distance between P and Q?

Excluding stoppages, the speed of a bus is 80 kmph and including stoppages, it is 60 kmph. For how many minutes does the bus stop per hour?