Luke drove from Town Z to Town A which was 624 km away. He started from Town Z at an average speed of 76 km/h. He maintained this speed for 4 h before increasing it by 6 km/h for the rest of the journey to Town A.
- How long did he take to complete the whole journey?
- What was his average speed from Town Z to Town A?
(a)
Distance of 1st part of the journey
= 4 x 76
= 304 km
New speed for rest of the journey
= 76 + 6
= 82 km / h
Remaining distance for rest of the journey
= 624 - 304
= 320 km
Time taken for rest of the journey
= 320 ÷ 82
= 4 h
Total time taken
= 4 + 4
= 8 h
(b)
Average speed of the whole journey
= 624 ÷ 8
= 78 km
Answer(s): (a) 8 h; (b) 78km/h