Arun alone can finish a work in 12 days and Shama alone can do it in 15 days. How much time will be taken to finish the work, if Arun and Shama work together?

A

$$5\frac{2}{3}$$ days

B

$$7\frac{1}{3}$$ days

C

$$5\frac{1}{3}$$ days

D

$$6\frac{2}{3}$$ days