Kathy left home at 9.50 a.m. and drove towards the mountain which was 972 km away. For the first 300 km, she was travelling at 75 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 300 km
= 300 ÷ 75
= 4 h
Distance of the remaining journey
= 972 - 300
= 672 km
Speed for remaining journey
= 75 + 9
= 84 km/h
Time taken to travel remaining journey
= 672 ÷ 84
= 8 h
Time taken to travel the whole journey
= 8 + 4
= 12 h
(b)
12 h after 9.50 a.m. = 9.50 p.m.
Answer(s): (a) 12 h; (b) 9.50 p.m.