A wheel travels a distance of 22 km in 2500 revolutions. What is the diameter of the wheel?

A train crosses two persons travelling at 3 kmph and 5 kmph in the same direction in 10 seconds and 11 seconds respectively. The speed of the train is:

Two buses start at the same time from Delhi and Agra, which are 300 km. apart, towards each other. After what time will they cross each other if their speeds are 38 km per hour and 37 km per hour?

A train travelling at the speed of 50 kmph leaves from a station. Another train travelling at speed of 60 kmph leaves the same station after 7 hours in the same direction. They will meet after what distance?

Two trains of length 120 m and 90 m respectively with the same speed pass a static pole in 8 seconds and 6 seconds respectively. In what time they will cross each other if they are moving in opposite directions?

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?

A boat running downstream covers 28 km in 7 hours, while for covering the same distance upstream it takes 14 hours. What is the speed of the boat in still water?

Two trains 128 meters and 122 meters long are running towards each other on parallel lines at 48 kmph and 42 kmph respectively. In what time will they clear off each other from the moment they meet?