At 8.55 a.m., Justin started driving from Town J to Town K which was 370 km away. For the first 150 km, he travelled at an average speed of 90 km/h. He then decreased his speed by 30 km/h and completed the remaining journey.
- Find the total time taken for the whole journey. Express your answer as a mixed number.
- At what time did she reach Town K?
(a)
Time taken for the first 150 km
= 150 ÷ 90
= 1
6090 = 1
23 h
Speed for the remaining journey
= 90 - 30
= 60 km/h
Remaining distance
= 370 - 150
= 220 km
Time taken for the remaining journey
= 220 ÷ 60
= 3
4060= 3
23 h
Total time taken
= 1
23 + 3
23= 1
23 + 3
23= 5
13 h
(b)
1 h = 60 min
13 h =
13 x 60 = 20 min
5 h 20 min after 8.55 a.m. = 2.15 p.m.
Answer(s): (a) 55
13 h; (b) 2.15 p.m.