Luke drove from Town T to Town U which was 400 km away. He started from Town T at an average speed of 70 km/h. He maintained this speed for 3 h before increasing it by 5 km/h for the rest of the journey to Town U.
- How long did he take to complete the whole journey?
- What was his average speed from Town T to Town U?
(a)
Distance of 1st part of the journey
= 3 x 70
= 210 km
New speed for rest of the journey
= 70 + 5
= 75 km / h
Remaining distance for rest of the journey
= 400 - 210
= 190 km
Time taken for rest of the journey
= 190 ÷ 75
= 2 h
Total time taken
= 3 + 2
= 5 h
(b)
Average speed of the whole journey
= 400 ÷ 5
= 80 km
Answer(s): (a) 5 h; (b) 80km/h