Kathy left home at 7.40 a.m. and drove towards the airport which was 920 km away. For the first 360 km, she was travelling at 72 km/h. Then she increased her speed by 8 km/h and completed the remaining journey.
- How long did she take for her whole journey?
- At what time did she reach the airport?
(a)
Time taken to travel 360 km
= 360 ÷ 72
= 5 h
Distance of the remaining journey
= 920 - 360
= 560 km
Speed for remaining journey
= 72 + 8
= 80 km/h
Time taken to travel remaining journey
= 560 ÷ 80
= 7 h
Time taken to travel the whole journey
= 7 + 5
= 12 h
(b)
12 h after 7.40 a.m. = 7.40 p.m.
Answer(s): (a) 12 h; (b) 7.40 p.m.