$A$ tank is filled in $5$ $hours$ by three pipes $A, B$ and $C$. Pipe $C$ is twice as fast as $B,$ and $B$ is twice as fast as $A$. How much time (in $hours$) will pipe $A$ alone take to fill the tank?

Three pipes $A, B$ and $C$ can fill a tank in $30 \ min$,$20 \ min$ and $10 \ min$,respectively. When the tank is empty,all the three pipes are opened. If $A, B$ and $C$ discharge chemical solutions $P, Q$ and $R$ respectively,then the part of solution $R$ in the liquid in the tank after $3 \ min$ is

Pipe $X$ can fill a tank in $20$ $hours$ and pipe $Y$ can fill the tank in $35$ $hours.$ Both the pipes are opened on alternate hours. Pipe $Y$ is opened first,then in how much time (in hours) will the tank be full?

$A$ booster pump can be used for filling as well as for emptying a tank. The capacity of the tank is $2400 m^3$. The emptying capacity of the tank is $10 m^3/min$ higher than its filling capacity and the pump needs $8$ minutes less to empty the tank than it needs to fill it. What is the filling capacity of the pump?

$A$ water tank is two-fifth full. Pipe $A$ can fill a tank in $10$ minutes,and pipe $B$ can empty it in $6$ minutes. If both the pipes are opened,how long will it take to empty or fill the tank completely?

$A$ water tank is $\frac{2}{5}$ full. Pipe $A$ can fill the tank in $10$ $minutes$ and pipe $B$ can empty it in $6$ $minutes$. If both the pipes are open,then how long will it take to empty or fill the tank completely?