Ian drove from Town H to Town J which was 462 km away. He started from Town H at an average speed of 70 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 70
= 210 km
New speed for rest of the journey
= 70 + 9
= 79 km / h
Remaining distance for rest of the journey
= 462 - 210
= 252 km
Time taken for rest of the journey
= 252 ÷ 79
= 3 h
Total time taken
= 3 + 3
= 6 h
(b)
Average speed of the whole journey
= 462 ÷ 6
= 77 km
Answer(s): (a) 6 h; (b) 77km/h