Pipes & Cisterns Mcqs

Q.  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 open, how long will it take to empty or fill the tank completely?

a. 6 min. to empty
b. 6 min. to full
c. 9 min. to empty
d. 9 min. to full


ANSWER: See Answer
 
Clearly, pipe B is faster than pipe A and so, the tank will be emptied.

Part to be emptied = 2/5
Part emptied by (A + B) in 1 minute = (1/6 – 1/10) = 1/15
1/15 : 2/5 :: 1 : x
x = (2/5 * 1 * 15) = 6 min.
So, the tank will be emptied in 6 min.
MCQs:  Two pipes A and B can fill a cistern in 12 and 15 minutes respectively. Both are opened together but after 3 minutes A is turned off. After how much more time will the cistern be filled?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Two pipes A and B can fill a tank in 4 and 5 hours respectively. If they are turned up alternately for one hour each, the time taken to fill the tank is?
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MCQs:  A cistern is filled by a tap in 3 1/2 hours. Due to leak in the bottom of the cistern, it takes half an hour longer to fill the cistern. If the cistern is full how long will it take the leak to empty it?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Two taps can separately fill a cistern 10 minutes and 15 minutes respectively and when the waste pipe is open, they can together fill it in 18 minutes. The waste pipe can empty the full cistern in?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 4 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Two pipes P and Q can fill a cistern in 12 and 15 minutes respectively. Both are opened together, but at the end of 3 minutes the first is turned off. How much longer will the cistern take to fill?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Two pipes A and B can separately fill a tank in 2 minutes and 15 minutes respectively. Both the pipes are opened together but 4 minutes after the start the pipe A is turned off. How much time will it take to fill the tank?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
MCQs:  Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
Category: Mathematics Quizzes,   Published by: T-Code Scripts
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