Ken drove from Town S to Town T which was 320 km away. He started from Town S at an average speed of 74 km/h. He maintained this speed for 2 h before increasing it by 6 km/h for the rest of the journey to Town T.
- How long did he take to complete the whole journey?
- What was his average speed from Town S to Town T?
(a)
Distance of 1st part of the journey
= 2 x 74
= 148 km
New speed for rest of the journey
= 74 + 6
= 80 km / h
Remaining distance for rest of the journey
= 320 - 148
= 172 km
Time taken for rest of the journey
= 172 ÷ 80
= 2 h
Total time taken
= 2 + 2
= 4 h
(b)
Average speed of the whole journey
= 320 ÷ 4
= 80 km
Answer(s): (a) 4 h; (b) 80km/h