A, B and C working alone can complete a work in 18, 27 and 36 days respectively. In how many days A, B and C together can complete 2/3 part of the same work?
Show answer & explanation
Correct answer: A
Explanation
A's work alone = 18 days
B's work alone = 27 days
C's work alone = 36 days
LCM of 18, 27, and 36 = 108
Total work = 108 units
A's work efficiency (per day) = 108/18 = 6 units
B's work efficiency (per day) = 108/27 = 4 units
C's work efficiency (per day) = 108/36 = 3 units
Combined work efficiency of A, B, and C (per day) -
= 6 + 4 + 3 = 13 units
2/3 of the total work = 108 × 2/3 = 72 units
Time taken to complete 72 units of work = 72/13 days