Michael drove from Town J to Town K which was 522 km away. He started from Town J at an average speed of 78 km/h. He maintained this speed for 2 h before increasing it by 5 km/h for the rest of the journey to Town K.
- How long did he take to complete the whole journey?
- What was his average speed from Town J to Town K?
(a)
Distance of 1st part of the journey
= 2 x 78
= 156 km
New speed for rest of the journey
= 78 + 5
= 83 km / h
Remaining distance for rest of the journey
= 522 - 156
= 366 km
Time taken for rest of the journey
= 366 ÷ 83
= 4 h
Total time taken
= 2 + 4
= 6 h
(b)
Average speed of the whole journey
= 522 ÷ 6
= 87 km
Answer(s): (a) 6 h; (b) 87km/h