two pipes p and q can fill a cistern in 12 minutes and 16 minutes respectively.  simultaneously both the pipes are opened together, then after how much time q should be closed so that the tank is full in 9 min ?

3 min

2 min

4 min

5 min

two pipes p and q can fill a cistern in 12 minutes and 16 minutes respectively.  simultaneously both the pipes are opened together, then after how much time q should be closed so that the tank is full in 9 min ?

10th-class-mcqs-all-subjects9th-class-mcqs-all-subjects11th-class-mcqs-past-papers12th-class-macqs-past-paperscss-islamiat-past-papers-mcqsnts-online-test-preparation