Gillian left home at 8.40 a.m. and drove towards the mountain which was 900 km away. For the first 480 km, she was travelling at 80 km/h. Then she increased her speed by 4 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 480 km
= 480 ÷ 80
= 6 h
Distance of the remaining journey
= 900 - 480
= 420 km
Speed for remaining journey
= 80 + 4
= 84 km/h
Time taken to travel remaining journey
= 420 ÷ 84
= 5 h
Time taken to travel the whole journey
= 5 + 6
= 11 h
(b)
11 h after 8.40 a.m. = 7.40 p.m.
Answer(s): (a) 11 h; (b) 7.40 p.m.