Subject
Quantitative Aptitude
Topic
Unitary Method
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:
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:
ক)
5 min.খ)
9 min.গ)
10 min.ঘ)
15 min.Explanation
Let B be turned off after x minutes. Then, Part filled by (A + B) in x min. + Part filled by A in (30 -x) min.= 1. So, x(2/75 + 1/45) + (30 - x) 2/75 = 1 => 11x/225 + (60 -2x)/75 = 1 => 11x + 180 - 6x = 225. => x = 9.Related questions
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