Oliver drove from Town H to Town J which was 616 km away. He started from Town H at an average speed of 75 km/h. He maintained this speed for 3 h before increasing it by 9 km/h for the rest of the journey to Town J.
- How long did he take to complete the whole journey?
- What was his average speed from Town H to Town J?
(a)
Distance of 1st part of the journey
= 3 x 75
= 225 km
New speed for rest of the journey
= 75 + 9
= 84 km / h
Remaining distance for rest of the journey
= 616 - 225
= 391 km
Time taken for rest of the journey
= 391 ÷ 84
= 4 h
Total time taken
= 3 + 4
= 7 h
(b)
Average speed of the whole journey
= 616 ÷ 7
= 88 km
Answer(s): (a) 7 h; (b) 88km/h