Risa left home at 5.30 a.m. and drove towards the mountain which was 1097 km away. For the first 474 km, she was travelling at 79 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 474 km
= 474 ÷ 79
= 6 h
Distance of the remaining journey
= 1097 - 474
= 623 km
Speed for remaining journey
= 79 + 10
= 89 km/h
Time taken to travel remaining journey
= 623 ÷ 89
= 7 h
Time taken to travel the whole journey
= 7 + 6
= 13 h
(b)
13 h after 5.30 a.m. = 6.30 p.m.
Answer(s): (a) 13 h; (b) 6.30 p.m.