A person walks a distance from point A to B at 15 km/h, and from point B to A at 30 km/h. If he takes 3 hours to complete the journey, then what is the distance from point A to B?

Let the distance between point A and B = 'd' km

Speed of the person from point A to B = 15 km/h

Time taken by the person to walk from point A to B = $$\frac{d}{15}$$ hours

Speed of the person from point B to A = 30 km/h

Time taken by the person to walk from point B to A = $$\frac{d}{30}$$ hours

Total time taken to complete the journey = 3 hours

$$=$$>  $$\frac{d}{15}+\frac{d}{30}=3$$

$$=$$>  $$\frac{2d+d}{30}=3$$

$$=$$>  $$\frac{3d}{30}=3$$

$$=$$>  $$d=30$$ km

$$\therefore\ $$Distance from point A to B = 30 km

Hence, the correct answer is Option B