Julian drove from Town M to Town N which was 355 km away. He started from Town M at an average speed of 60 km/h. He maintained this speed for 2 h before increasing it by 7 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
= 2 x 60
= 120 km
New speed for rest of the journey
= 60 + 7
= 67 km / h
Remaining distance for rest of the journey
= 355 - 120
= 235 km
Time taken for rest of the journey
= 235 ÷ 67
= 3 h
Total time taken
= 2 + 3
= 5 h
(b)
Average speed of the whole journey
= 355 ÷ 5
= 71 km
Answer(s): (a) 5 h; (b) 71km/h