Eric drove from Town A to Town B which was 445 km away. He started from Town A at an average speed of 79 km/h. He maintained this speed for 4 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
= 4 x 79
= 316 km
New speed for rest of the journey
= 79 + 9
= 88 km / h
Remaining distance for rest of the journey
= 445 - 316
= 129 km
Time taken for rest of the journey
= 129 ÷ 88
= 1 h
Total time taken
= 4 + 1
= 5 h
(b)
Average speed of the whole journey
= 445 ÷ 5
= 89 km
Answer(s): (a) 5 h; (b) 89km/h