A cistern can be filled by pipe P in 3 hours and pipe Q in 5 hours and empty by pipe R in 2 hours. If all these pipes are open, then in how many hours the cistern will be full?
A cistern can be filled by pipe P in 3 hours and pipe Q in 5 hours and empty by pipe R in 2 hours. If all these pipes are open, then in how many hours the cistern will be full?
[A]10 hours
[B]15 hours
[C]30 hours
[D]Cannot be filled
30 hours
Because as per the question part of the cistern filled by all pipes in an hour
So, the cistern will be filled in 30 hours if all pipes are open.
Hence option [C] is correct answer.
