Question : 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?
Option 1: 9 days
Option 2: 10.5 days
Option 3: 8 days
Option 4: 7.5 days
Correct Answer: 9 days
Solution :
According to the question
(A + B + C)'s 1 day work =
(A + B)'s 1 day work =
B's 1 day work =
⇒ (A + C)'s 1 day work =
⇒ Time taken by A and C together =
Hence, the correct answer is 9 days.