A, B, and C together can complete a task in 6 days. If A alone takes 12 days and B alone takes 18 days, how long will C alone take?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 36 days
Total work = LCM of 6, 12 and 18 = 36 units
A’s efficiency = 36/12 = 3 units
B’s efficiency = 36/18 = 2 units
(A + B + C)’s efficiency = 36/6 = 6 units
C’s efficiency = 6 − (3 + 2) = 1 unit
Therefore, time taken by C alone = 36/1 = 36 days.