Problema Solution

Three pipes, A,B, and C, are often used two at a time to fill a tank. When A and B are used together, the tank is filled in 5 minutes. When either A and C or B and C are used together, the tank is filled in 3 minutes. How long would it take each pipe alone to fill the tank?

Answer provided by our tutors

5/a + 5/b =1

3/a + 3/c = 1

3/b +3/c =1

subtracting 2 from 3,

3/a - 3/b = 0

therefore a = b

using this in 1,

a = 10 hrs and b = 10 hrs

using this in 2nd equation,

3/10 + 3/c = 1

3/c = 1-  .3 = .7

c = 3/.7 = 4.28 hrs