Question

a tap fill an empty tank in 5 hours and tap b can empty tank in 6 hour how long will it take to fill a tank if both taps are opened

Answer 1

A can empty in 5 hours

B can empty in 6 hours

A can empty part of tank in 1 hour = 1/5

B can empty part of tank in 1 hour = 1/6

both can empty in 1 hour together = 1/5 + 1/6 = (6+5)/30 = 11/30

So they can empty it in 30/11 = 2 8/11 hours

Answer 2

the correct answer is 2.545454 or 28/11 hours