Pipes A and B can fill a tank in 20 hours and 30 hours respectively and pipe C can empty the full tank in 40 hours. If all the pipes are opened together, how much time will be needed to make the tank full ?

Five litres of water is added to a certain quantity of pure milk costing Rs. 60 per litre. If by selling the mixture at the same price as before, a profit of 20% is made, then the amount of pure milk in the mixture is :

Pipes A and B can fill a tank in 5 hours and 6 hours respectively. Another Pipe can empty the full tank in 30 hours. If all three pipes are opened together, then the tank will be filled in :

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 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 shopkeeper has 10 litres of pure honey. He sells honey at the cost price of Rs. 300 per litre. After mixing some quantity of water in pure honey he sells the syrup of pure honey and water at Rs. 250 per litre. The quantity of water mixed in pure honey is

Two inlet pipes can fill a tank in 20 minutes and 24 minutes respectively . An outlet pipe can empty 30 liters of water per minute. If all three pipes working together can fill the tank in 15 minutes. The capacity of the tank is :