Risa left home at 8.10 a.m. and drove towards the mountain which was 634 km away. For the first 219 km, she was travelling at 73 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 219 km
= 219 ÷ 73
= 3 h
Distance of the remaining journey
= 634 - 219
= 415 km
Speed for remaining journey
= 73 + 10
= 83 km/h
Time taken to travel remaining journey
= 415 ÷ 83
= 5 h
Time taken to travel the whole journey
= 5 + 3
= 8 h
(b)
8 h after 8.10 a.m. = 4.10 p.m.
Answer(s): (a) 8 h; (b) 4.10 p.m.