Mark drove from Town H to Town J which was 288 km away. He started from Town H at an average speed of 61 km/h. He maintained this speed for 3 h before increasing it by 9 km/h for the rest of the journey to Town J.
- How long did he take to complete the whole journey?
- What was his average speed from Town H to Town J?
(a)
Distance of 1st part of the journey
= 3 x 61
= 183 km
New speed for rest of the journey
= 61 + 9
= 70 km / h
Remaining distance for rest of the journey
= 288 - 183
= 105 km
Time taken for rest of the journey
= 105 ÷ 70
= 1 h
Total time taken
= 3 + 1
= 4 h
(b)
Average speed of the whole journey
= 288 ÷ 4
= 72 km
Answer(s): (a) 4 h; (b) 72km/h