Mary left home at 6.35 a.m. and drove towards the mountain which was 991 km away. For the first 255 km, she was travelling at 85 km/h. Then she increased her speed by 7 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 255 km
= 255 ÷ 85
= 3 h
Distance of the remaining journey
= 991 - 255
= 736 km
Speed for remaining journey
= 85 + 7
= 92 km/h
Time taken to travel remaining journey
= 736 ÷ 92
= 8 h
Time taken to travel the whole journey
= 8 + 3
= 11 h
(b)
11 h after 6.35 a.m. = 5.35 p.m.
Answer(s): (a) 11 h; (b) 5.35 p.m.