A train travels the distance between station P and Q at a speed of 126 km/h, while in the opposite direction it comes back at 90 km/h. Another train travels the same distance at the average speed of the first train. The time taken by the second train to travel 525 km is:

In a kilometer race, A can give B a start of 100 m or 15 seconds. How long does A take to complete the race?

If the speed of the boat in still water is 20 km / h and the speed of the stream is 5 km / h, then how long will it take for the ferry to travel 100 km with the speed of the stream?

A man travelled a distance of 60 kms in 10 hours . He travelled partly on foot at 5 kms per hour and partly on bicycle at 7 kms per hour . What is the distance travelled on foot ? 

Vishnu travelled equal distances at speeds of 10 km/hr, 30 km/hr and 8 km/hr and took a total of 15.5 minute to complete. Find the total distance he travelled in km.

The ratio of speeds of A is to B is 2:3 and therefore A takes 20 minutes less time than B takes. What is the ratio of time taken by A and B?

The two trains cross each other in 12 seconds, moving in the opposite direction, and they take 60 seconds to travel in the same direction. both trains can have speed in (m/sec).

Speed of boat in still water is 9 km/hr. Stream speed initially is 2 km/hr but it increases by 3 km/hr after every hour. Find the time after which boat will come back to the position where it started.(in hour)