Fred drove from Town D to Town E which was 350 km away. He started from Town D at an average speed of 64 km/h. He maintained this speed for 4 h before increasing it by 8 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
= 4 x 64
= 256 km
New speed for rest of the journey
= 64 + 8
= 72 km / h
Remaining distance for rest of the journey
= 350 - 256
= 94 km
Time taken for rest of the journey
= 94 ÷ 72
= 1 h
Total time taken
= 4 + 1
= 5 h
(b)
Average speed of the whole journey
= 350 ÷ 5
= 70 km
Answer(s): (a) 5 h; (b) 70km/h