Julian drove from Town A to Town B which was 504 km away. He started from Town A at an average speed of 63 km/h. He maintained this speed for 3 h before increasing it by 5 km/h for the rest of the journey to Town B.
- How long did he take to complete the whole journey?
- What was his average speed from Town A to Town B?
(a)
Distance of 1st part of the journey
= 3 x 63
= 189 km
New speed for rest of the journey
= 63 + 5
= 68 km / h
Remaining distance for rest of the journey
= 504 - 189
= 315 km
Time taken for rest of the journey
= 315 ÷ 68
= 4 h
Total time taken
= 3 + 4
= 7 h
(b)
Average speed of the whole journey
= 504 ÷ 7
= 72 km
Answer(s): (a) 7 h; (b) 72km/h