Onethirdof a certain journey is covered at the rate of25 $$\frac{km}{hour}$$, one-fourth at the rate of ‘30 $$\frac{km}{hour}$$ and the rest at 50 $$\frac{km}{hour}$$. The averagé speed the whole journey is

A

35 $$\frac{km}{hour}$$

B

33 $$\frac{1}{3}$$ $$\frac{km}{hour}$$

C

30 $$\frac{km}{hour}$$

D

33 $$\frac{1}{12}$$ $$\frac{km}{hour}$$