Bobby drove from Town U to Town V which was 480 km away. He started from Town U at an average speed of 73 km/h. He maintained this speed for 3 h before increasing it by 7 km/h for the rest of the journey to Town V.
- How long did he take to complete the whole journey?
- What was his average speed from Town U to Town V?
(a)
Distance of 1st part of the journey
= 3 x 73
= 219 km
New speed for rest of the journey
= 73 + 7
= 80 km / h
Remaining distance for rest of the journey
= 480 - 219
= 261 km
Time taken for rest of the journey
= 261 ÷ 80
= 3 h
Total time taken
= 3 + 3
= 6 h
(b)
Average speed of the whole journey
= 480 ÷ 6
= 80 km
Answer(s): (a) 6 h; (b) 80km/h