Two pipes P and Q can fill a cistern in 12 min. and 15 min. respectively but a third pipe ‘R’ can empty the full tank in 6 min.  P and Q are kept open for 5 min. in the beginning and then ‘R’ is also opened.  In what time is the cistern emptied ?

Related Mcqs:

Twenty women can do a work in sixteen days. Sixteen men can complete the same work in fifteen days. What is the ratio between the capacity of a man and a woman ?

A. 3 : 4 B. 4 : 3 C. 5 : 3 D. Data inadequate...

A cistern has two taps which fill it in 12 min. and 15 min.respectively   There is one outlet pipe in the cistern.  When all the taps & pipe are opened, the empty cistern is full in 20 min.  How long will the waste pipe (outlet) take to empty the full cistern ?

A. 10 min B. 20 min C. 30 min D. 40 min...

P, Q and R can complete a work in 24, 6 and 12 days respectively. The work will be completed in________days if all of them are working together.

A. 2 B. 3 3⁄7 C. 4 ¼ D. 5...

P is able to do a piece of work in 15 days and Q can do the same work in 20 days. If they can work together for 4 days, what is the fraction of work left?

A. 8/15 B. 7/15 C. 11/15 D. 2/11...

Two taps X and Y can fill a tank in 10 hrs. and 15 hrs.respectively.  If the both taps are opened together, the tank will be full in_________?

A. 3 hrs. B. 4 hrs, C. 5 hrs. D. 6 hrs....