Advertisements
Advertisements
Question
A and B together can do a piece of work in 12 days, while B alone can finish it in 30 days. A alone can finish the work in
Options
15 days
18 days
20 days
25 days
MCQ
Solution
20 days
Explanation:
(A + B)'s 1 day's work = `1/12`
B's 1 day's work = `1/30`
∴ A's 1 day's work = `1/12-1/30`
= `(5-2)/60=1/20`
Second Method
Here, x = 12 and y = 30
∴ Required number of days = `(xy)/(y-x)=(12xx30)/(30-12)`
= `(12xx30)/18` = 20 days
A alone can finish the work in 20 days.
shaalaa.com
Time and Work (Entrance Exam)
Is there an error in this question or solution?
