A can do a piece of work in 15 days and B in 20 days. They began the work together but 5 days before the completion of the work, A leaves. The work was completed in?	Choose the most appropriate option.
A) 8 days B) 10 days C) 15 days D) 11 3/7 days E) None of these
Explanation:   (x â€“ 5)/15 + x/20 = 1   x = 11 3/7 days   ANSWER IS 11 3/7 days
<result>D</result>
A can do a piece of work in 15 days and B in 20 days. They began the work together but 5 days before the completion of the work, A leaves. The work was completed in?