Two pipes, A and B, can fill a cistern in 10 minutes and 12 minutes respectively. Pipe C can empty the cistern in 15 minutes. If all 3 pipes are opened together, how long will it take to fill the cistern completely?

If a person goes 20 kilometre downstream in 5 hours and returns against the stream in 15 hours, then the speed of the stream in kilometre per hour is :

A motor boat goes 20 km downstream and comes back to the starting point in 6 hours. If the speed of the boat in still water is 12 km/h, then the speed of the stream is :

A vessel contains 56 litres of mixture of milk and water in the ratio 5:2. How much water should be mixed with it so that the milk to water ratio becomes 4:5

A boat takes 6 hr 25 minutes to row upstream a certain distance with a speed which is 14.4 times that of the river current. The time taken by the boat to row down the same distance with same speed is:

A motor boat can row at the speed of 12 kilometres per hour in Still water . if the river is flowing at 4 kilometer per hour and it takes 12 hours for a round trip , then the distance between the two places is

A man rows 8 km upstream in 4 hours and 16 km downstream in 4 hours . What is the speed of the current?