City K and City L were 416 km apart. A sedan travelled from City K towards City L. At the same time, a van started from City L to City K. After travelling 1
23 h, the two vehicles were still 156 km apart. If the ratio of the average speed of the van to that of the sedan was 6 : 7, find
- the average speed of the sedan.
- the time taken for them to meet travelling the rest of the journey. Express your answer in h.
(a)
Distance covered in 1
23 h by the two vehicles
= 416 - 156
= 260 km
Combined speed of the two vehicles
= 260 ÷
53 = 260 x
35 = 156 km/h
Average speed of the van : Average speed of the sedan = 6 : 7
6 u + 7 u = 13 u
13 u = 156
1 u = 156 ÷ 13 = 12
Average speed of the sedan
= 7 u
= 7 x 12
= 84 km/h
(b)
Time taken for the van and the sedan to meet travelling the rest of the journey
= 156 ÷ 156
= 1 h
Answer(s): (a) 84 km/h; (b) 1 h