Julian drove from Town L to Town M which was 664 km away. He started from Town L at an average speed of 66 km/h. He maintained this speed for 3 h before increasing it by 4 km/h for the rest of the journey to Town M.
- How long did he take to complete the whole journey?
- What was his average speed from Town L to Town M?
(a)
Distance of 1st part of the journey
= 3 x 66
= 198 km
New speed for rest of the journey
= 66 + 4
= 70 km / h
Remaining distance for rest of the journey
= 664 - 198
= 466 km
Time taken for rest of the journey
= 466 ÷ 70
= 5 h
Total time taken
= 3 + 5
= 8 h
(b)
Average speed of the whole journey
= 664 ÷ 8
= 83 km
Answer(s): (a) 8 h; (b) 83km/h