Working 8 hours a day, A can finish an assignment in 12 days while B takes 2 days less to finish it, working 2 hours more than A, every day. The contractor decides to put them to work together on the assignment. Each working day now is 8 hours. How many days will they take to finish the assignment?

A completes the work in 12 days at 8 hour per day = 12 x 8 = 96 hours
In 1 hour, A completes (1/96) amount of work

B completes the work in 10 days (2 days less than A) working 10 hours every day (i.e. 2 hours more than A per day) = 10 x 10 = 100 hours
In 1 hour, B completes (1/100) amount of work

Working together, in 1 hour A and B complete (1/96) + (1/100) = (49/2400) amount of work
So they complete the entire work in (2400/49) hours

Since they work for 8 hours per day, they need = (2400/49) × (1/8) = 300/49 days.