Three pipes A, B and C can fill cistern in 6 hours. After working at it together for 2 hours, C is closed and A and B fill it in 7 hours more. The time taken by C alone to fill the cistern is
1). 14 hours
2). 15 hours
3). 16 hours
4). 17 hours
An empty tank can be filled by pipe A in 4 hours and by pipe B in 6 hours. If the two pipes are opened for 1 hour each alternately with first opening pipe A, then the tank will be filled in
1). $1\frac{3}{4}$ hours
2). $2\frac{3}{5}$ hours
3). $4\frac{2}{3}$ hours
4). $5\frac{1}{2}$ hours
A tank has a leak which would empty the completely filled tank in 10 hours. If the tank is full of water and a tap is opened which admits 4 litres of water per minute in the tank, the leak takes 15 hours to empty the tank. How many litres of water does the tank hold
1). 2400 L
2). 4500 L
3). 1200 L
4). 7200 L
A tank can be filled with water by two pipes A and B together in 36 minutes. If the pipe B was stopped after 30 minutes, the tank is filled in 40 minutes. The pipe B can alone fill the tank in
1). 45 minutes
2). 60 minutes
3). 75 minutes
4). 90 minutes
A tap takes 36 hours extra to fill a tank due to a leakage equivalent to half of its inflow. The inflow can fill the tank in how many hours
1). 36 hrs
2). 24 hrs
3). 30 hrs
4). 18 hrs