X can complete a work in 5 days and Y in 10 days. If they work on it together for 2 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. .
(X + Y)'s 1-day work = 1/5 + 1/10 = 3/10
2-day work = 2 × 3/10 = 3/5
Left work = 1 - 3/5 = 2/5