Glen drove from Town C to Town D which was 534 km away. He started from Town C at an average speed of 75 km/h. He maintained this speed for 3 h before increasing it by 4 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 75
= 225 km
New speed for rest of the journey
= 75 + 4
= 79 km / h
Remaining distance for rest of the journey
= 534 - 225
= 309 km
Time taken for rest of the journey
= 309 ÷ 79
= 3 h
Total time taken
= 3 + 3
= 6 h
(b)
Average speed of the whole journey
= 534 ÷ 6
= 89 km
Answer(s): (a) 6 h; (b) 89km/h