A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in
A). 3 days
B). 5 days
C). 8 days
D). 10 days
10 days
(B + C)'s 1 day's work = 1/9 + 1/12 = 7/36 .
Work done by B and C in 3 days = 7/36 x 3 = 7/12
.
Remaining work = 1 - 7/12 = 5/12
.
Now, 1/24 work is done by A in 1 day.
So, 5/12 work is done by A in 24 x 5/12 = 10 days.