City S and City T were 528 km apart. A sedan travelled from City S towards City T. At the same time, a van started from City T to City S. After travelling 1
15 h, the two vehicles were still 330 km apart. If the ratio of the average speed of the van to that of the sedan was 5 : 6, 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
15 h by the two vehicles
= 528 - 330
= 198 km
Combined speed of the two vehicles
= 198 ÷
65 = 198 x
56 = 165 km/h
Average speed of the van : Average speed of the sedan = 5 : 6
5 u + 6 u = 11 u
11 u = 165
1 u = 165 ÷ 11 = 15
Average speed of the van
= 5 u
= 5 x 15
= 75 km/h
(b)
Time taken for the van and the sedan to meet travelling the rest of the journey
= 330 ÷ 165
= 2 h
Answer(s): (a) 75 km/h; (b) 2 h