A, B and C working alone can complete a work in 9, 12 and 18 days respectively. In how many days A, B and C together can complete the same work?
Show answer & explanation
Correct answer: C
Explanation
A's work in 1 day = 1/9
B's work in 1 day = 1/12
C's work in 1 day = 1/18
Combined work of all three in 1 day = 1/9 + 1/12 + 1/18
= (4 + 3 + 2) / 36
= 9/36
= 1/4
Therefore, time taken to complete the entire work = 4 days