Question

john takes 15 minutes to walk from school to the bus station. Jim takes 20 minutes to walk from school to the bus station. If the difference in their speeds is 2 km/h, how far is the station from school

Answer 1

Let x km/h be the Jim's speed. If the difference in Jim's and John's speeds is 2 km/h, then the John's speed is x+2 km/h.

1. John takes 15 minutes to walk with speed x+2 km/h from school to the bus station, then the distance is 15·(x+2) km.

2. Jim takes 20 minutes to walk with speed x km/h from school to the bus station, then the distance is 20·x km.

3. The distance is the same, so

20x=15(x+2),

20x=15x+30,

20x-15x=30,

5x=30,

x=30:5,

x=6.

Answer: the distance between the station and the school is 6 km.