X and Y can do a piece of work in 20 days and 12 days respectively. X started the work alone and then after 4 days Y joined him till the completion of the work. How long did the work last ?

A. 15 days

B. 20 days

C. 6 days

D. 10 days
Be the first to comment if anything wrong with this mcq
Your comment successfully submitted!
It will automatically posted after review and approval by our staff member.