A, B and C together can do a piece of work in 6 days. A and B together can do the same work in 12 days. B alone can do the same work in 18 days. In how many days can A and C together do the same work?
Answer & explanation
Correct answer: option 1
A + B + C = 6 days,
A + B = 12 days,
B = 18 days,
⇒ A + B + C = 6 (Efficiency)
⇒ A + C + 2 = 6,
⇒ A + C = 4,
⇒ Time required by A + C to complete the work = \(\frac{36}{4}\) = 9 days, ..(\(\frac{Work}{Efficiency}\) = Time)