A jug has two holes. The Ist hole alone makes the jug empty in 15 minutes and $$2^{nd}$$ hole alone makes the jug empty in 20 minutes. If water leaks out at a constant rate, how long in minutes does it lake if both the holes together empty the jug?

A

$$\frac{4}{7}$$

B

$$7\frac{4}{7}$$

C

$$8\frac{5}{7}$$

D

$$8\frac{4}{7}$$