Question

Pipe A and Pipe B together can fill a tank in 12 hours and Pipe B alone can do it in 18 hours. How many hours Pipe A alone takes to fill the tank?
1. 18 hours
2. 24 hours
3. 36 hours
4. 40 hours

Answer 1

Correct Answer - Option 3 : 36 hours

Given:

Pipe A and Pipe B together can fill a tank in = 12 hours

Pipe B alone can fill the tank in = 18 hours

Calculation:

Pipe (A + B)’s 1 day’s work = 1/12

Pipe B’s 1 day’s work = 1/18

∴ Pipe A‘s 1 day’s work = 1/12 - 1/18

⇒ (3 – 2)/36

⇒ 1/36

⇒ 36 hours

∴ Pipe A alone takes 36 hours to fill the tank.