Question

Three pipes A, B and C can fill a tank in 6 min., 8 min, and 12 min. respectively. The pipe C is closed for 4 min before the tank is filled. In what time would the tank be fill?

Answer 1

Let the tank be full in x min. Then,

\(\frac{X}{6}+\frac{X}{8}\) + \(\frac{X-4}{12}\) = 1 \(\Rightarrow\) \(\frac{4X+3X+2(X-4)}{24}\) = 1

\(\Rightarrow\) 9x – 8 = 24

\(\Rightarrow\) 9x = 32

\(\Rightarrow\) x = \(3\frac{5}{9}\) min