The distance between City E and City F was 810 km apart. A lorry travelled at an average speed of 90 km/h from City E to City F. At the same time, a bus travelled at an average speed of 72 km/h from City F to City E. How much further did the lorry travel than the bus when the lorry met the bus on the way?
Combined speed of the lorry and the bus
= 90 + 72
= 162 km/h
Time taken for the lorry and the bus to meet
= 810 ÷ 162
= 5 h
Difference in the speed between the lorry and the bus
= 90 - 72
= 18 km/h
Distance that the lorry travelled further than the bus
= 5 x 18
= 90 km
Answer(s): 90 km