City H and City J were 468 km apart. A sedan travelled from City H towards City J. At the same time, a van started from City J to City H. After travelling 1
14 h, the two vehicles were still 288 km apart. If the ratio of the average speed of the van to that of the sedan was 4 : 5, find
- the average speed of the van.
- 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
= 468 - 288
= 180 km
Combined speed of the two vehicles
= 180 ÷
54 = 180 x
45 = 144 km/h
Average speed of the van : Average speed of the sedan = 4 : 5
4 u + 5 u = 9 u
9 u = 144
1 u = 144 ÷ 9 = 16
Average speed of the van
= 4 u
= 4 x 16
= 64 km/h
(b)
Time taken for the van and the sedan to meet travelling the rest of the journey
= 288 ÷ 144
= 2 h
Answer(s): (a) 64 km/h; (b) 2 h