At 9.50 a.m., Ken started driving from Town T to Town U which was 420 km away. For the first 210 km, he travelled at an average speed of 70 km/h. He then decreased his speed by 10 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 U?
(a)
Time taken for the first 210 km
= 210 ÷ 70
= 3/1
= 3 h
Speed for the remaining journey
= 70 - 10
= 60 km/h
Remaining distance
= 420 - 210
= 210 km
Time taken for the remaining journey
= 210 ÷ 60
= 3
3060= 3
12 h
Total time taken
= 3 + 3
12= 3/1 + 3
12= 6
12 h
(b)
1 h = 60 min
12 h =
12 x 60 = 30 min
6 h 30 min after 9.50 a.m. = 4.20 p.m.
Answer(s): (a) 66
12 h; (b) 4.20 p.m.