Brandon drove from Town H to Town J which was 280 km away. He started from Town H at an average speed of 68 km/h. He maintained this speed for 2 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
= 2 x 68
= 136 km
New speed for rest of the journey
= 68 + 9
= 77 km / h
Remaining distance for rest of the journey
= 280 - 136
= 144 km
Time taken for rest of the journey
= 144 ÷ 77
= 2 h
Total time taken
= 2 + 2
= 4 h
(b)
Average speed of the whole journey
= 280 ÷ 4
= 70 km
Answer(s): (a) 4 h; (b) 70km/h