Betty left home at 9.30 a.m. and drove towards the mountain which was 666 km away. For the first 378 km, she was travelling at 63 km/h. Then she increased her speed by 9 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 378 km
= 378 ÷ 63
= 6 h
Distance of the remaining journey
= 666 - 378
= 288 km
Speed for remaining journey
= 63 + 9
= 72 km/h
Time taken to travel remaining journey
= 288 ÷ 72
= 4 h
Time taken to travel the whole journey
= 4 + 6
= 10 h
(b)
10 h after 9.30 a.m. = 7.30 p.m.
Answer(s): (a) 10 h; (b) 7.30 p.m.