1.

A cistern can be filled with water by a pipe in 5 hours and it can be emptied by a second pipe in 4 hours. If both the pipes are opened when the cistern is full, the time in which it will be emptied is :

A. 9 hours
B.
C. 18 hours
D.
E. 20 hours
Answer» D.


Discussion

No Comment Found

Related MCQs