Question

A contractor has two teams of workers : team A and team B. Team A can complete a job in 8 days and team B can do the same job in 16 days. Team A starts working on the job and team B joins A after 2 days. Team A withdraws after 3 more days. Number of days for which team B should further work to complete the job is

Answer 1

7 days is the answer 
[16+2]-[8+3]
18-11
=7