Will drove from Town W to Town X which was 630 km away. He started from Town W at an average speed of 63 km/h. He maintained this speed for 4 h before increasing it by 9 km/h for the rest of the journey to Town X.
- How long did he take to complete the whole journey?
- What was his average speed from Town W to Town X?
(a)
Distance of 1st part of the journey
= 4 x 63
= 252 km
New speed for rest of the journey
= 63 + 9
= 72 km / h
Remaining distance for rest of the journey
= 630 - 252
= 378 km
Time taken for rest of the journey
= 378 ÷ 72
= 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