An outlet pipe can empty a cistern in $3$ $h$. In what time (in $h$) will the pipe empty two-third part of the cistern?

$A$ pump can fill a tank with water in $2$ $hours$. Because of a leak,it took $2 \frac{1}{3}$ $hours$ to fill the tank. The leak can drain all the water of the tank in (in $hours$)?

$A$ pipe can fill a tank with thrice the speed of another pipe. If both the pipes together take $36$ $min$ to fill an empty tank completely,then how much time will it take for the slower pipe to fill the tank alone?

$A, B$ and $C$ are three pipes connected to a tank. $A$ and $B$ together fill the tank in $6 \text{ h}$,$B$ and $C$ together fill the tank in $10 \text{ h}$ and $A$ and $C$ together fill the tank in $12 \text{ h}$. In how much time will $A, B$ and $C$ fill up the tank together?

Two pipes can fill a cistern separately in $24$ $minutes$ and $40$ $minutes$ respectively. $A$ waste pipe can drain off $30 \text{ litres per minute}$. If all the three pipes are opened,the cistern fills in one $hour$. The capacity (in $litres$) of the cistern is:

Two pipes $A$ and $B$ can fill a tank in $15$ minutes and $20$ minutes respectively. Both the pipes are opened together but after $4$ minutes,pipe $A$ is turned off. What is the total time required to fill the tank?