$A$ 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 $hours$)?

Two pipes $A$ and $B$ can fill a water tank in $10$ and $12$ $min,$ respectively,and a third pipe $C$ can empty it at the rate of $6$ $gallons$ per $min.$ If $A, B,$ and $C$ are opened together,they fill the tank in $20$ $min.$ What is the capacity (in $gallons$) of the tank?

If two pipes function simultaneously,the reservoir will be filled in $12$ $hours$. One pipe fills the reservoir $10$ $hours$ faster than the other. How many $hours$ does the faster pipe take to fill the reservoir?

Three pipes $A, B$ and $C$ can fill a tank from empty to full in $30$ minutes,$20$ minutes and $10$ minutes respectively. When the tank is empty,all the three pipes are opened. $A, B$ and $C$ discharge chemical solutions $P, Q$ and $R$ respectively. What is the proportion of solution $R$ in the liquid in the tank after $3$ minutes?

Two pipes $A$ and $B$ can fill a cistern in $24$ $minutes$ and $30$ $minutes$,respectively. There is also an outlet $C$. If all the three pipes are opened together,the cistern is full in $20$ $minutes$. How much time (in $minutes$) will be taken by outlet $C$ to empty the full cistern?

$A$ water tank has two taps $A$ and $B$. Tap $A$ can fill it in $6$ hours,and tap $B$ can empty it in $5$ hours. If both taps are opened simultaneously,how much time (in hours) is required to empty the tank?