Question:
Three pipes A, B, C can empty a tank in 10 hours, 15 hours, 30 hours respectively. If all the three pipes are open simultaneously how much time will the tank be empty.
A5 hours
B6 hours
C8 hours
D12 hours
Answer:
A. 5 hours
Explanation:
time = 1/A + 1/B + 1/C = 1/10 + 1/15 + 1/30 = (3+2+1) / 30 = 6/30 = 1/5 => 5 hours