7. Two pipes A and B can fill a cistern in 37 1/2
minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
| Useful Links From This Website |
| Notifications, Admit Cards, Results, Universities |
| Books, Exam Pattern, Mock Tests, Study Materials, Syllabus, Test Papers |
A. 15 min.
B. 5 min.
C. 9 min.
D. 10 min.
