Question

4 pipes can fill a reservoir in 15, 20, 30 and
..60 hours respectively. The first was opened
at 6 a.m., second at 7 a.m., third at 8 a.m.,
and the fourth at 9 a.m. When will the reservoir
be filled up?
1] 1 a.m.
2] 4 p.m.
4] 4 a.m.
371 p.m.​

Answer 1

Answer:

I think 4 p.m. is the answer