"A and B can separately do a piece of work in 20 and 15 days respectively.
Channel: Doubtnut
Date: 2020-04-05

"A and B can separately do a piece of work in 20 and 15 days respectively. They worked together for 6 days, after which B was replaced by C. If work was finished in next 4 days, then the number of days in which C alone could do the work will be
a. `30`
b. `40`
c. `35`
d. `60\ `"