A can do a piece of work in 24 days and B can do the same work in 30 days. If they work on it together for 8 days, then the fraction of the work that is left is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
Given that
A can do a piece of work in 24 days
B can do the same work in 30 days
Total work = LCM (24, 30) = 120
The efficiency of A = 120/24 = 5
The efficiency of B = 120/30 = 4
Total work of one day if they work together = 4 + 5 = 9
if they work for 8 days, work done = 8 × 9 = 72
Remaining work = 120 - 72 = 48
Hence, the fraction of the work that is left = 48/120 = 2/5