A can complete a work in 10 days and B can complete it in 15 days. If they work on it together for 5 days, then the fraction of the work left will be:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 1/6
A can do the work = 10 days
B can do the work = 15 days
Total work = LCM of the 10 and 15 = 30
Efficiency of A = 30/10 = 3
Efficiency of B = 30/15 = 2
Their 5 days work = (3 + 2) × 5 = 25
Remainig work = 30 - 25 = 5 unit
Fraction of the remaining work = 5/30 = 1/6