Julian drove from Town Z to Town A which was 492 km away. He started from Town Z at an average speed of 73 km/h. He maintained this speed for 4 h before increasing it by 7 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 73
= 292 km
New speed for rest of the journey
= 73 + 7
= 80 km / h
Remaining distance for rest of the journey
= 492 - 292
= 200 km
Time taken for rest of the journey
= 200 ÷ 80
= 2 h
Total time taken
= 4 + 2
= 6 h
(b)
Average speed of the whole journey
= 492 ÷ 6
= 82 km
Answer(s): (a) 6 h; (b) 82km/h