Warren drove from Town J to Town K which was 486 km away. He started from Town J at an average speed of 69 km/h. He maintained this speed for 3 h before increasing it by 6 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
= 3 x 69
= 207 km
New speed for rest of the journey
= 69 + 6
= 75 km / h
Remaining distance for rest of the journey
= 486 - 207
= 279 km
Time taken for rest of the journey
= 279 ÷ 75
= 3 h
Total time taken
= 3 + 3
= 6 h
(b)
Average speed of the whole journey
= 486 ÷ 6
= 81 km
Answer(s): (a) 6 h; (b) 81km/h