Valen drove from Town B to Town C which was 435 km away. He started from Town B at an average speed of 64 km/h. He maintained this speed for 4 h before increasing it by 7 km/h for the rest of the journey to Town C.
- How long did he take to complete the whole journey?
- What was his average speed from Town B to Town C?
(a)
Distance of 1st part of the journey
= 4 x 64
= 256 km
New speed for rest of the journey
= 64 + 7
= 71 km / h
Remaining distance for rest of the journey
= 435 - 256
= 179 km
Time taken for rest of the journey
= 179 ÷ 71
= 1 h
Total time taken
= 4 + 1
= 5 h
(b)
Average speed of the whole journey
= 435 ÷ 5
= 87 km
Answer(s): (a) 5 h; (b) 87km/h