Pierre drove from Town Y to Town Z which was 581 km away. He started from Town Y at an average speed of 67 km/h. He maintained this speed for 3 h before increasing it by 8 km/h for the rest of the journey to Town Z.
- How long did he take to complete the whole journey?
- What was his average speed from Town Y to Town Z?
(a)
Distance of 1st part of the journey
= 3 x 67
= 201 km
New speed for rest of the journey
= 67 + 8
= 75 km / h
Remaining distance for rest of the journey
= 581 - 201
= 380 km
Time taken for rest of the journey
= 380 ÷ 75
= 4 h
Total time taken
= 3 + 4
= 7 h
(b)
Average speed of the whole journey
= 581 ÷ 7
= 83 km
Answer(s): (a) 7 h; (b) 83km/h