A can do a work in $$7\frac{1}{2}$$ days, whereas B can do the same work in $$10\frac{1}{2}$$ days. If they worked together, then the same work would be completed in

A

$$4\frac{3}{8}$$ days

B

4 days

C

$$4\frac{1}{2}$$ days

D

$$4\frac{1}{8}$$ days