A pipe can fill a tank in 22/3 hours, and another pipe…

A pipe can fill a tank in $2\frac{2}{3}$ hours, and another pipe empties it in 4 hours. If both are opened together, how long will it take to fill the tank?

Show answer & explanation

Correct answer: A

Explanation

Filling time = $2\frac{2}{3}$ hours = 8/3 hours, Emptying time = 4 hours

Combined work = (1 / Filling time) − (1 / Emptying time)

Filling rate = 1 ÷ (8/3) = 3/8

Emptying rate = 1/4

Combined rate = 3/8 − 1/4

= 3/8 − 2/8

= 1/8

Time = 1 ÷ (1/8) = 8 hours

SSC CPO 2025 PYQ — Question 112