A B And C can do a piece of work in 11, 20 and 55 days respectively, working alone. How soon the work can be done if A is assisted by B and C on alternate days.
6
7
8
9
10
6
7
8
9
10
i get 8
days when A, B, C work together, 1/11+1/20+1/55=35/220=7/44 work done.
days when A works alone, 1/11 or 4/44 of work done.
so say in 4 days 7/44+4/44+7/44+4/44=22/44=1/2 work done
=>full work done in 4*2=8 days
