A started a ,work and left after working for 2 days. Then B was called and he finished the work in 9 days. had A left the work after working for 3 days, B would have finished the remaining work in 6 days. In how many days can each of them, working alone, finish the whole work ?

• A. .5 days, 7.5 days
• B. days, 8.5 days
• C. days, 15 days
• D. one of these