Two workers A and B are engaged to do a piece of work. Working alone, A takes 8 hours more to complete the work than if both worked together. On the,other hand, working alone, 8 would need 4(1/2) hours more to complete the work than if both worked together. How much time would they take to complete the job working together
a. 4 hours
b. 5 hours
c. 6 hours
d. 7 hours