Jeremy drove from Town B to Town C which was 474 km away. He started from Town B at an average speed of 77 km/h. He maintained this speed for 4 h before increasing it by 8 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 77
= 308 km
New speed for rest of the journey
= 77 + 8
= 85 km / h
Remaining distance for rest of the journey
= 474 - 308
= 166 km
Time taken for rest of the journey
= 166 ÷ 85
= 2 h
Total time taken
= 4 + 2
= 6 h
(b)
Average speed of the whole journey
= 474 ÷ 6
= 79 km
Answer(s): (a) 6 h; (b) 79km/h