Two pipes A and B can independently fill a tank completely in 20 and 30 minutes respectively. If both the pipes are opened simultaneously, how much time will they take to fill the tank completely?
12 mins
To solve such type of questions, we will first know that how much tank is filled by both the pipes in 1 minute and after getting that result, we will simply add them as shown: Now the time taken by pipe A to completely fill the tank is 20 minutes, while time taken by pipe B to completely fill the tank is 30 minutes. Initially we will find quantity of water filled by both pipes in a tank in 1 minute. Quantity of water filled by pipe A in a tank 1 min = 1/20 Quantity of water filled by pipe B in a tank in 1 min = 1/30 So total Quantity of water filled by both pipes A and B ie (A+B) in 1 min = 1/20 + 1/30 = 1/12 So we see that both pipes A and B can fill the tank in 12 minutes, which is option B.
Important Questions from Pipe and Cistern
The compound interest on Rs. 64,000 for 3 years, compounded annually at 7.5% p.a. is
A water tank can be emptied in 40 minutes by a pipe of d 'diameter, so how long will it take for a 2d diameter pipe to be emptied?
A pipe can fill a tank in 4 hours, while a leak which is at one-fourth of the height of the tank from bottom can empty upto that part in 2 hours. If both are operated simultaneously and initially the tank is full, then when it will be one-fourth full?
Two pipes can fill a tank in 10 hrs and 12 hrs, respectively, while the third can empty it in 20 hrs. If all the pipes are opened together, how much time will it take for the tank to be filled up?
Two pipes X and Y can fill an empty tank in 16 hours and 20 hours respectively. Pipe Z alone can empty the completely filled tank in 25 hours. Firstly both pipes X and Y are opened and after 6 hours pipe Z is also opened. What will be the total time (in hours) taken to completely fill the tank?
