Albert drove from Town M to Town N which was 648 km away. He started from Town M at an average speed of 66 km/h. He maintained this speed for 4 h before increasing it by 10 km/h for the rest of the journey to Town N.
- How long did he take to complete the whole journey?
- What was his average speed from Town M to Town N?
(a)
Distance of 1st part of the journey
= 4 x 66
= 264 km
New speed for rest of the journey
= 66 + 10
= 76 km / h
Remaining distance for rest of the journey
= 648 - 264
= 384 km
Time taken for rest of the journey
= 384 ÷ 76
= 4 h
Total time taken
= 4 + 4
= 8 h
(b)
Average speed of the whole journey
= 648 ÷ 8
= 81 km
Answer(s): (a) 8 h; (b) 81km/h