Albert drove from Town X to Town Y which was 468 km away. He started from Town X at an average speed of 77 km/h. He maintained this speed for 3 h before increasing it by 8 km/h for the rest of the journey to Town Y.
- How long did he take to complete the whole journey?
- What was his average speed from Town X to Town Y?
(a)
Distance of 1st part of the journey
= 3 x 77
= 231 km
New speed for rest of the journey
= 77 + 8
= 85 km / h
Remaining distance for rest of the journey
= 468 - 231
= 237 km
Time taken for rest of the journey
= 237 ÷ 85
= 3 h
Total time taken
= 3 + 3
= 6 h
(b)
Average speed of the whole journey
= 468 ÷ 6
= 78 km
Answer(s): (a) 6 h; (b) 78km/h