If A can do a work in 24 days and B can do it in 16 days, how long will it take for both to complete the work if they work together for 8 days?
Answer: C. 14 days
In 8 days, A and B together complete 8*(1/24 + 1/16) = 8*(5/48) = 5/6 of the work, leaving 1/6 of the work. They will take an additional 2 days to finish the remaining work.