Carl drove from Town J to Town K which was 468 km away. He started from Town J at an average speed of 73 km/h. He maintained this speed for 4 h before increasing it by 7 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 73
= 292 km
New speed for rest of the journey
= 73 + 7
= 80 km / h
Remaining distance for rest of the journey
= 468 - 292
= 176 km
Time taken for rest of the journey
= 176 ÷ 80
= 2 h
Total time taken
= 4 + 2
= 6 h
(b)
Average speed of the whole journey
= 468 ÷ 6
= 78 km
Answer(s): (a) 6 h; (b) 78km/h