City Y and City Z were 462 km apart. A car travelled from City Y towards City Z. At the same time, a lorry started from City Z to City Y. After travelling 1
12 h, the two vehicles were still 264 km apart. If the ratio of the average speed of the lorry to that of the car was 5 : 6, find
- the average speed of the car.
- the time taken for them to meet travelling the rest of the journey. Express your answer in h.
(a)
Distance covered in 1
12 h by the two vehicles
= 462 - 264
= 198 km
Combined speed of the two vehicles
= 198 ÷
32 = 198 x
23 = 132 km/h
Average speed of the lorry : Average speed of the car = 5 : 6
5 u + 6 u = 11 u
11 u = 132
1 u = 132 ÷ 11 = 12
Average speed of the car
= 6 u
= 6 x 12
= 72 km/h
(b)
Time taken for the lorry and the car to meet travelling the rest of the journey
= 264 ÷ 132
= 2 h
Answer(s): (a) 72 km/h; (b) 2 h