City Y and City Z were 546 km apart. A van travelled from City Y towards City Z. At the same time, a bus started from City Z to City Y. After travelling 1
12 h, the two vehicles were still 312 km apart. If the ratio of the average speed of the bus to that of the van was 6 : 7, 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
12 h by the two vehicles
= 546 - 312
= 234 km
Combined speed of the two vehicles
= 234 ÷
32 = 234 x
23 = 156 km/h
Average speed of the bus : Average speed of the van = 6 : 7
6 u + 7 u = 13 u
13 u = 156
1 u = 156 ÷ 13 = 12
Average speed of the van
= 7 u
= 7 x 12
= 84 km/h
(b)
Time taken for the bus and the van to meet travelling the rest of the journey
= 312 ÷ 156
= 2 h
Answer(s): (a) 84 km/h; (b) 2 h