Question : A and B working together can do a piece of work in
Option 1: 3 hours
Option 2: 2 hours
Option 3: 2.5 hours
Option 4: 3.25 hours
Correct Answer: 2 hours
Solution :
Amount of work done by A and B in 1 hour =
Amount of work done by B and C in 1 hour =
Amount of work done by A and C in 1 hour =
Adding all the equations, we have:
⇒ 2 × (A + B + C)'s 1 hour work =
⇒ 2 × (A + B + C)'s 1 hour work =
⇒ (A + B + C)'s 1 hour work =
(A + B + C) can finish
(A + B + C) can finish the total work in 2 hours.
Hence, the correct answer is 2 hours.
