City V and City W were 351 km apart. A car travelled from City V towards City W. At the same time, a van started from City W to City V. After travelling 1
14 h, the two vehicles were still 216 km apart. If the ratio of the average speed of the van to that of the car was 4 : 5, 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
14 h by the two vehicles
= 351 - 216
= 135 km
Combined speed of the two vehicles
= 135 ÷
54 = 135 x
45 = 108 km/h
Average speed of the van : Average speed of the car = 4 : 5
4 u + 5 u = 9 u
9 u = 108
1 u = 108 ÷ 9 = 12
Average speed of the car
= 5 u
= 5 x 12
= 60 km/h
(b)
Time taken for the van and the car to meet travelling the rest of the journey
= 216 ÷ 108
= 2 h
Answer(s): (a) 60 km/h; (b) 2 h