Zeph drove from Town B to Town C which was 581 km away. He started from Town B at an average speed of 79 km/h. He maintained this speed for 4 h before increasing it by 6 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 79
= 316 km
New speed for rest of the journey
= 79 + 6
= 85 km / h
Remaining distance for rest of the journey
= 581 - 316
= 265 km
Time taken for rest of the journey
= 265 ÷ 85
= 3 h
Total time taken
= 4 + 3
= 7 h
(b)
Average speed of the whole journey
= 581 ÷ 7
= 83 km
Answer(s): (a) 7 h; (b) 83km/h