The speed of a  boat in still water is 20 kmph and the rate of current is 4 kmph. The distance travelled by the boat downstream in 30 minute is

Two places P and Q are 92 km apart. A train leaves P for Q and at the same time another train leaves Q for P. Both the trains meet 4 hrs after they start moving. If the train travelling from P to Q travels 7 km/hr faster than the other train, find the speed of the two trains.

A passenger train leaves Calcutta at 4 PM and travels at the rate of 30 kilometres an hour. The mail train leaves Calcutta at 9 PM and travels, on a parallel line of rails, at the rate of 45 km an hour, when will the second train overtake the first?

Ram and Shyam are travelling from point A to B, which are 60 km apart. Travelling at a certain speed ram takes one hour more than Shyam to reach point B. If Ram doubles his speed he will take 30 minutes less than Shyam to reach point B. At what speed was Ram driving from point A to B ?

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?

A train of length 212 meter is running at 45 km/h. In what time (in seconds) will it cross a platform of length 188 meter?

A and B started travelling towards each other at the same time, from Place X to Y and Y to X, respectively. After crossing each other, A and B took 2.45 hours and 4.05 hours to reach Y and X, respectively. If the speed of B was 8.4 km/h, then what was the speed (in km/h) of A?

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?