AFCAT II 2015 Solved Paper

As given C does half as much work as A and B together
(A+B) can do it in 20 days
(A+B) s 1 days wok =1∕20.
A's 1 day work : B's 1 day Work =1∕2:1=1:2
A's 1 day work =(1∕20)×(1∕3)=(1∕60) [Divide 1∕20 in the ratio 1:2 ]
B's 1 day work =(1∕20)×(2∕3)=1∕30
(A+B+C) 's 1 day work =(1∕60)+(1∕30)+(1∕40)=9∕120=3∕40
All the three together will finish it in 40∕3=13.33 days.