Q. Both X and Y together can complete a work in 12 days and Y alone can complete the same work in 30 days. In how many days will X alone complete the work?
A) 20
B) 15
C) 16
D) 18
✔ Correct Answer: 20
Exam Insight
Using the work formula: Total work = LCM of 12 and 30 = 60 units. X and Y together = 5 units/day, Y alone = 2 units/day. Thus, X alone = 5 − 2 = 3 units/day. Total time = 60 / 3 = 20 days.