George drove from Town E to Town F which was 664 km away. He started from Town E at an average speed of 69 km/h. He maintained this speed for 4 h before increasing it by 4 km/h for the rest of the journey to Town F.
- How long did he take to complete the whole journey?
- What was his average speed from Town E to Town F?
(a)
Distance of 1st part of the journey
= 4 x 69
= 276 km
New speed for rest of the journey
= 69 + 4
= 73 km / h
Remaining distance for rest of the journey
= 664 - 276
= 388 km
Time taken for rest of the journey
= 388 ÷ 73
= 4 h
Total time taken
= 4 + 4
= 8 h
(b)
Average speed of the whole journey
= 664 ÷ 8
= 83 km
Answer(s): (a) 8 h; (b) 83km/h