Ken drove from Town E to Town F which was 360 km away. He started from Town E at an average speed of 72 km/h. He maintained this speed for 3 h before increasing it by 5 km/h for the rest of the journey to Town F.
- How long did he take to complete the whole journey?
- What was his average speed from Town E to Town F?
(a)
Distance of 1st part of the journey
= 3 x 72
= 216 km
New speed for rest of the journey
= 72 + 5
= 77 km / h
Remaining distance for rest of the journey
= 360 - 216
= 144 km
Time taken for rest of the journey
= 144 ÷ 77
= 1 h
Total time taken
= 3 + 1
= 4 h
(b)
Average speed of the whole journey
= 360 ÷ 4
= 90 km
Answer(s): (a) 4 h; (b) 90km/h