Ruchi, Khushi and Teju can do a piece of work in 30, 40 and 60 days respectively. In how many days can Ruchi do the work, if she is assisted by both Khushi and Teju on every third day?

A

$$\frac{550}{12}$$ days

B

$$\frac{85}{4}$$ days

C

$$\frac{71}{2}$$ days

D

$$\frac{360}{7}$$ days