Bryan drove from Town M to Town N which was 336 km away. He started from Town M at an average speed of 77 km/h. He maintained this speed for 2 h before increasing it by 8 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 77
= 154 km
New speed for rest of the journey
= 77 + 8
= 85 km / h
Remaining distance for rest of the journey
= 336 - 154
= 182 km
Time taken for rest of the journey
= 182 ÷ 85
= 2 h
Total time taken
= 2 + 2
= 4 h
(b)
Average speed of the whole journey
= 336 ÷ 4
= 84 km
Answer(s): (a) 4 h; (b) 84km/h