The distance between City J and City K was 620 km apart. A lorry travelled at an average speed of 85 km/h from City J to City K. At the same time, a car travelled at an average speed of 70 km/h from City K to City J. How much further did the lorry travel than the car when the lorry met the car on the way?
Combined speed of the lorry and the car
= 85 + 70
= 155 km/h
Time taken for the lorry and the car to meet
= 620 ÷ 155
= 4 h
Difference in the speed between the lorry and the car
= 85 - 70
= 15 km/h
Distance that the lorry travelled further than the car
= 4 x 15
= 60 km
Answer(s): 60 km