Asher drove from Town C to Town D which was 316 km away. He started from Town C at an average speed of 70 km/h. He maintained this speed for 3 h before increasing it by 10 km/h for the rest of the journey to Town D.
- How long did he take to complete the whole journey?
- What was his average speed from Town C to Town D?
(a)
Distance of 1st part of the journey
= 3 x 70
= 210 km
New speed for rest of the journey
= 70 + 10
= 80 km / h
Remaining distance for rest of the journey
= 316 - 210
= 106 km
Time taken for rest of the journey
= 106 ÷ 80
= 1 h
Total time taken
= 3 + 1
= 4 h
(b)
Average speed of the whole journey
= 316 ÷ 4
= 79 km
Answer(s): (a) 4 h; (b) 79km/h