A travels a certain distance with three different speeds, first covers 3 km with a speed of 9 km / h, the second 6 km with a speed of 15 km / h and the third 9 km with a speed of 18 km / h. What is the average speed of A.s entire journey?

Options

A. `(460)/(37)` km/h
B. `(540)/(37)` km/h
C. `(660)/(37)` km/h
D. `(480)/(37)` km/h

Answer

B