Two taps $P$ and $Q$ can fill a water tank in $12$ $min$ and $15$ $min$ respectively. They are opened together,but after $3$ $min$,tap $P$ is closed. How much more time will $Q$ take to fill the remaining part of the tank?

Taps $A, B$ and $C$ are attached to a tank. The rates of water flow through them are $42 \ L/h$,$56 \ L/h$,and $48 \ L/h$ respectively. $A$ and $B$ are inlet taps,while $C$ is an outlet tap. If all the taps are opened simultaneously,the tank is filled in $16 \ h$. What is the capacity of the tank (in $L$)?

Two pipes can fill an empty tank separately in $24$ $minutes$ and $40$ $minutes$ respectively,and a third pipe can empty $30$ $gallons$ of water per $minute$. If all three pipes are opened,the empty tank becomes full in one $hour$. The capacity of the tank (in $gallons$) is:

$A$ 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 $hours$)?

$A$ cistern has three pipes $A, B$ and $C$. Pipes $A$ and $B$ can fill it in $3 \, h$ and $4 \, h$, respectively, while pipe $C$ can empty the completely filled cistern in $1 \, h$. If pipes are opened in order at $3:00 \, pm$, $4:00 \, pm$ and $5:00 \, pm$, respectively, at what time will the cistern be empty?

$A$ pipe fills a water tank three times faster than another pipe. If the two pipes together can fill the empty tank in $36$ $minutes$,then how much time will the slower pipe alone take to fill the tank?