Dylan drove from Town T to Town U which was 630 km away. He started from Town T at an average speed of 74 km/h. He maintained this speed for 4 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
= 4 x 74
= 296 km
New speed for rest of the journey
= 74 + 5
= 79 km / h
Remaining distance for rest of the journey
= 630 - 296
= 334 km
Time taken for rest of the journey
= 334 ÷ 79
= 3 h
Total time taken
= 4 + 3
= 7 h
(b)
Average speed of the whole journey
= 630 ÷ 7
= 90 km
Answer(s): (a) 7 h; (b) 90km/h