The distance between City R and City S was 990 km apart. A lorry travelled at an average speed of 86 km/h from City R to City S. At the same time, a convertible travelled at an average speed of 79 km/h from City S to City R. How much further did the lorry travel than the convertible when the lorry met the convertible on the way?
Combined speed of the lorry and the convertible
= 86 + 79
= 165 km/h
Time taken for the lorry and the convertible to meet
= 990 ÷ 165
= 6 h
Difference in the speed between the lorry and the convertible
= 86 - 79
= 7 km/h
Distance that the lorry travelled further than the convertible
= 6 x 7
= 42 km
Answer(s): 42 km