Question

Four pipes can fill a reservoir in 15, 20, 30 and 60 hours respectively. the first one was opened at 6 am, second at 7 am, third at 8 am and the fourth at 9 am. when will the reservoir be filled ? (a) 11 am (b) 12 noon (c) 1 pm (d) 1:30 pm

Answer 1

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