Charlie drove from Town B to Town C which was 602 km away. He started from Town B at an average speed of 68 km/h. He maintained this speed for 3 h before increasing it by 8 km/h for the rest of the journey to Town C.
- How long did he take to complete the whole journey?
- What was his average speed from Town B to Town C?
(a)
Distance of 1st part of the journey
= 3 x 68
= 204 km
New speed for rest of the journey
= 68 + 8
= 76 km / h
Remaining distance for rest of the journey
= 602 - 204
= 398 km
Time taken for rest of the journey
= 398 ÷ 76
= 4 h
Total time taken
= 3 + 4
= 7 h
(b)
Average speed of the whole journey
= 602 ÷ 7
= 86 km
Answer(s): (a) 7 h; (b) 86km/h