The distance between City W and City X was 810 km apart. A lorry travelled at an average speed of 91 km/h from City W to City X. At the same time, a car travelled at an average speed of 71 km/h from City X to City W. 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
= 91 + 71
= 162 km/h
Time taken for the lorry and the car to meet
= 810 ÷ 162
= 5 h
Difference in the speed between the lorry and the car
= 91 - 71
= 20 km/h
Distance that the lorry travelled further than the car
= 5 x 20
= 100 km
Answer(s): 100 km