Charlie drove from Town D to Town E which was 592 km away. He started from Town D at an average speed of 60 km/h. He maintained this speed for 3 h before increasing it by 10 km/h for the rest of the journey to Town E.
- How long did he take to complete the whole journey?
- What was his average speed from Town D to Town E?
(a)
Distance of 1st part of the journey
= 3 x 60
= 180 km
New speed for rest of the journey
= 60 + 10
= 70 km / h
Remaining distance for rest of the journey
= 592 - 180
= 412 km
Time taken for rest of the journey
= 412 ÷ 70
= 5 h
Total time taken
= 3 + 5
= 8 h
(b)
Average speed of the whole journey
= 592 ÷ 8
= 74 km
Answer(s): (a) 8 h; (b) 74km/h