Warren drove from Town J to Town K which was 355 km away. He started from Town J at an average speed of 62 km/h. He maintained this speed for 4 h before increasing it by 8 km/h for the rest of the journey to Town K.
- How long did he take to complete the whole journey?
- What was his average speed from Town J to Town K?
(a)
Distance of 1st part of the journey
= 4 x 62
= 248 km
New speed for rest of the journey
= 62 + 8
= 70 km / h
Remaining distance for rest of the journey
= 355 - 248
= 107 km
Time taken for rest of the journey
= 107 ÷ 70
= 1 h
Total time taken
= 4 + 1
= 5 h
(b)
Average speed of the whole journey
= 355 ÷ 5
= 71 km
Answer(s): (a) 5 h; (b) 71km/h