A can finish a work in 24 days, B can finish it in 18 days, and C can finish it in 12 days. If they work together, how long will they take to complete the work?
Answer: B. 6 days
The combined work rate of A, B, and C is 1/24 + 1/18 + 1/12 = 1/6. Therefore, they will complete the work in 6 days.