Pipes and Cisterns

Two pipes can fill a tank in $8 \mathrm{h}$ and $12 \mathrm{h}$ respectively whereas an escape pipe can empty it in $6 \mathrm{h}$. If the three pipes are opened at $1$ PM, $2$ PM and $3$ PM respectively, at what time will the tank be filled?

Which of the following statements are necessary to answer the question:

A tank is fitted with two taps A and B. In how much time will the tank be full if both the taps are opened together ?
(i) A is $50$% more efficient than B
(ii) A alone takes $16$ hours to fill the tank
(iii) B alone takes $24$ hours to fill the tank.

Six pipes are fitted to a water tank. Some of these are filling pipes, others are emptying pipes. Each filling pipes can fill the tank in 9 hrs and each waste pipe can empty the tank in$6 \mathrm{hrs}$. On opening all the pipes in the empty tank is filled in $9 \mathrm{hrs}$. Find the number of filling pipes?

The discharge of pipe A is $200 \mathrm{liters}$ per hour and that of pipe B is $300 \mathrm{liters}$ per hour while that of pipe C is $250 \mathrm{liters}$ per hour. A and B are used to fill the tank while C is used to empty the tank. If B and C are open alternately with pipe A, then find the time required to fill a tank of capacity $4500 \mathrm{litres}$.

A large tanker can be filled by two pipes $A$ and $B$ in $60 \min$ and $40 \min$ respectively. How many minutes will take to fill the empty tanker if only $B$ is used in the first half of the time and $A$ and $B$ both are used in the second half of the time?

Two pipes A and B, Pipe A can fill the tank in $250 \min$, it is operational for $50 \min$, Pipe B is also opened along with pipe B and fill the remaining tank in $150 \min$. Find the time taken by pipe B alone to fill the tank.

The time taken by pipe A to fill the tank is $1 \mathrm{hour}$, the time is taken by pipe B to fill the tank is $2 \mathrm{hours}$ and the time is taken by pipe C to empty the tank is $1.5 \mathrm{hours}$. Pipe A and pipe B is opened together for $4 \mathrm{hours}$ and then pipe C is opened. Find the time taken by pipe C to empty the tank.

Two pipes can fill a tank in $20$ minutes and $30$ minutes respectively. If both the pipes are opened simultaneously, then in how many minutes the tank will be filled?

$15 \mathrm{hours}$ of rain can fill $60\%$of a pond. A man can empty the pond in $50 \mathrm{hours}$. The pond was completely empty when it started raining. If it rained for $12 \mathrm{hours}$ , how much time will it take for the man to empty the Pond ?
 

Jaya and Sachin use a straw to drink juice from the same vessel. Jaya alone takes $2 \mathrm{minutes}$ to drink $20 \mathrm{ml}$ of the juice and Sachin alone takes $1 \mathrm{minute}$ to drink $20 \mathrm{ml}$of juice. They drink together and empty a full vessel in $2 \mathrm{minutes}$. After the vessel gets empty, a refilling straw that can fill $400 \mathrm{ml}$ in $8$ $\mathrm{minutes}$ is also put in the vessel. In how much time will the container be full if all the straws are simultaneously used?

Two machines fill a juice container. Machine B is $62.5\%$ as efficient as Machine A. If Machine A fills the tank completely in $2.5 \mathrm{hours}$, how much time will it take for both the machines to fill $65\%$ of the container ?
 

Pipe A can fill a tank in $36 \mathrm{minutes}$ and Pipe B can empty the tank in $45 \mathrm{minutes}$. If both the pipes are opened simultaneously, then find the time (in $\mathrm{hours}$) to fill the tank to half its capacity.

Pipe D1 can fill an empty tank in $80 \min$ and Pipe D2 can empty the same tank in $100 \min$. If pipes are opened simultaneously, then in how much time the tank gets completely filled?

Two pipes can fill a tank in $20$ minutes and $30$ minutes respectively. If both the pipes are opened simultaneously, then in how many minutes the tank will be filled?

A water tank of $1000 \mathrm{L}$ capacity is connected to a tap which can fill it at the rate of $20 \mathrm{L}/\min$ and water is let out at the same time at the rate of $5 \mathrm{L}/\min$. After an hour the outlet is shut off. Find how long (in minutes) will it take now for the tank to become full.

A pipe fills an empty tank in $2$ hours. Due to leakage in the bottom of tank, pipe takes $30$ minutes more to fill the tank. What time (in hours) will the leak take to empty the full tank if the pipe is closed?

Three taps A, B and C fill tank in $20$ min, $15$ min and $12$ min, respectively. If all the taps are opened simultaneously, how long (in minutes) will they take to fill $40\%$ of the drum?

Pipes $A$, $B$ and $C$ can fill a tank in $15, 30$ and $40 \mathrm{hours}$, respectively. Pipes $A, B$ and $C$ are opened at $6 \mathrm{A}.\mathrm{M}., 8 \mathrm{A}.\mathrm{M}.,$ and $10 \mathrm{A}.\mathrm{M}.,$ respectively, on the same day. When will the tank be full?

Two pipes can fill a tank in $15 \mathrm{hours}$ and $4 \mathrm{hours}$, respectively, while a third pipe can empty it in $12 \mathrm{hours}$. How long (in $\mathrm{hours}$) will it take to fill the empty tank if all the three pipes are opened simultaneously?

A pump can fill a tank with water in $3 \mathrm{hours}$. Because of a leak, it took $3\frac{1}{3} \mathrm{hours}$ to fill the tank. In how many hours can the leak alone drain all the water of the tank when it is full?