Carl drove from Town V to Town W which was 688 km away. He started from Town V at an average speed of 79 km/h. He maintained this speed for 4 h before increasing it by 6 km/h for the rest of the journey to Town W.
- How long did he take to complete the whole journey?
- What was his average speed from Town V to Town W?
(a)
Distance of 1st part of the journey
= 4 x 79
= 316 km
New speed for rest of the journey
= 79 + 6
= 85 km / h
Remaining distance for rest of the journey
= 688 - 316
= 372 km
Time taken for rest of the journey
= 372 ÷ 85
= 4 h
Total time taken
= 4 + 4
= 8 h
(b)
Average speed of the whole journey
= 688 ÷ 8
= 86 km
Answer(s): (a) 8 h; (b) 86km/h