Two pipes $A$ and $B$ can fill a tank in $30$ $minutes$ and $45$ $minutes$ respectively. Pipe $C$ can empty the full tank in $36$ $minutes$. Initially,pipes $A$ and $B$ are opened. After $12$ $minutes$,pipe $C$ is also opened. What is the total time (in $minutes$) required to fill the tank?

$A$ tap can fill the cistern in $8$ hours and another can empty it in $16$ hours. If both the taps are opened simultaneously,the time (in hours) to fill the tank is?

Two taps $A$ and $B$ can fill a water tank in $20$ $min$ and $24$ $min$ respectively,and a third tap $C$ empties the tank at a rate of $3$ $gallons$ per $min$. If all three taps $A$,$B$,and $C$ are opened together,the tank is filled in $15$ $min$. What is the capacity of the tank in $gallons$?

$A$ swimming pool has $3$ drain pipes. The first two pipes $A$ and $B$,operating simultaneously,can empty the pool in half the time that $C$ (the $3rd$ pipe) alone takes to empty it. Pipe $A$,working alone,takes half the time taken by pipe $B$. Together they take $6$ $hours$ $40$ $minutes$ to empty the pool. Time taken by pipe $A$ to empty the pool,in hours,is

Three pipes $A$,$B$,and $C$ can fill a cistern in $10$,$12$,and $15$ $hours$,respectively,while working alone. If all the three pipes are opened together,the time taken to fill the cistern will be:

Two pipes can fill a tank in $20$ $minutes$ and $24$ $minutes$ respectively,and a waste pipe can empty $3$ $gallons$ per minute. All the three pipes working together can fill the tank in $15$ $minutes$. The capacity of the tank is (in $gallons$):