A can do a piece of the work in 10 days and B in 20 days. They begin together but A leaves 2 days before the completion of the work. The whole work will be done in?
Correct Answer: 8 days
Explanation:
Let the required days be x.
A works for (x - 2) days, while B work for x days.
According to the question
(x - 2)/10 + x/20 = 1
⇒ 2x - 4 + x = 20
∴ 3x = 24
⇒ x = 8 days
