Michael drove from Town C to Town D which was 445 km away. He started from Town C at an average speed of 71 km/h. He maintained this speed for 2 h before increasing it by 8 km/h for the rest of the journey to Town D.
- How long did he take to complete the whole journey?
- What was his average speed from Town C to Town D?
(a)
Distance of 1st part of the journey
= 2 x 71
= 142 km
New speed for rest of the journey
= 71 + 8
= 79 km / h
Remaining distance for rest of the journey
= 445 - 142
= 303 km
Time taken for rest of the journey
= 303 ÷ 79
= 3 h
Total time taken
= 2 + 3
= 5 h
(b)
Average speed of the whole journey
= 445 ÷ 5
= 89 km
Answer(s): (a) 5 h; (b) 89km/h