Valen drove from Town Z to Town A which was 395 km away. He started from Town Z at an average speed of 72 km/h. He maintained this speed for 3 h before increasing it by 10 km/h for the rest of the journey to Town A.
- How long did he take to complete the whole journey?
- What was his average speed from Town Z to Town A?
(a)
Distance of 1st part of the journey
= 3 x 72
= 216 km
New speed for rest of the journey
= 72 + 10
= 82 km / h
Remaining distance for rest of the journey
= 395 - 216
= 179 km
Time taken for rest of the journey
= 179 ÷ 82
= 2 h
Total time taken
= 3 + 2
= 5 h
(b)
Average speed of the whole journey
= 395 ÷ 5
= 79 km
Answer(s): (a) 5 h; (b) 79km/h