Question

If three pipes are open together, a tank is filled in 10 hrs. one of the taps can fill in 5 hrs and another in 10 hrs. at what rate does the 3rd pipe work?

Answer 1

Let the 3 pipes be A,B and C

A can fill it in 5 hrs

B can fill it in 10 hrs

A+B+C can fill it in 10 hrs

Take LCM of all the three terms (5,10,10) = 10 = total capacity of tank

A fill 10/5 = 2 unit of tank in 1 hr

B can fill 10/10 = 1 unit of tank in 1 hr

A+B+C = 10  in 1 hr

So, 2 + 1 +C = 10

C = 7 units in 1 hr

C will fill the tank in 10/7 hrs