Vincent drove from Town A to Town B which was 438 km away. He started from Town A at an average speed of 71 km/h. He maintained this speed for 2 h before increasing it by 9 km/h for the rest of the journey to Town B.
- How long did he take to complete the whole journey?
- What was his average speed from Town A to Town B?
(a)
Distance of 1st part of the journey
= 2 x 71
= 142 km
New speed for rest of the journey
= 71 + 9
= 80 km / h
Remaining distance for rest of the journey
= 438 - 142
= 296 km
Time taken for rest of the journey
= 296 ÷ 80
= 4 h
Total time taken
= 2 + 4
= 6 h
(b)
Average speed of the whole journey
= 438 ÷ 6
= 73 km
Answer(s): (a) 6 h; (b) 73km/h