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?

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. 6 days
B. 10 days
C. 15 days
D. 20 days

Answer: B.


Time and Work

Learn More Multiple Choice Question :