Sarah left home at 8.30 a.m. and drove towards the mountain which was 814 km away. For the first 430 km, she was travelling at 86 km/h. Then she increased her speed by 10 km/h and completed the remaining journey.
- How long did she take for her whole journey?
- At what time did she reach the mountain?
(a)
Time taken to travel 430 km
= 430 ÷ 86
= 5 h
Distance of the remaining journey
= 814 - 430
= 384 km
Speed for remaining journey
= 86 + 10
= 96 km/h
Time taken to travel remaining journey
= 384 ÷ 96
= 4 h
Time taken to travel the whole journey
= 4 + 5
= 9 h
(b)
9 h after 8.30 a.m. = 5.30 p.m.
Answer(s): (a) 9 h; (b) 5.30 p.m.