A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :

A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :

A can do a work in 15 days and B in 20 days. If they work on it together for 4 days, then the fraction of the work that is left is :


A. 1/4
B. 1/10
C. 7/15
D. 8/15


Answer: D.