A & B can do a work in 8 days, B & C can do the same work in 12 days. A, B & C together can finish it in 6 days. A & C together will do it in :

A 4 Days

B 6 Days

C 8 Days

D 12 Days

Correct Answer: Option C

in 1 day,

A + B = 1/8

B + C = 1/12

A + B + C = 1/6

Only A does in 1 day = (1/6 - 1/12) = 1/12

Only B does in 1 day = (1/8 - 1/12) = 1/24

Only C does in 1 day = (1/12- 1/24) = 1/24

So Both A & C do in 1 day = (1/12 + 1/24) = 3/24 = 1/8

So they complete the job in 8 days