Howard drove from Town L to Town M which was 602 km away. He started from Town L at an average speed of 78 km/h. He maintained this speed for 4 h before increasing it by 5 km/h for the rest of the journey to Town M.
- How long did he take to complete the whole journey?
- What was his average speed from Town L to Town M?
(a)
Distance of 1st part of the journey
= 4 x 78
= 312 km
New speed for rest of the journey
= 78 + 5
= 83 km / h
Remaining distance for rest of the journey
= 602 - 312
= 290 km
Time taken for rest of the journey
= 290 ÷ 83
= 3 h
Total time taken
= 4 + 3
= 7 h
(b)
Average speed of the whole journey
= 602 ÷ 7
= 86 km
Answer(s): (a) 7 h; (b) 86km/h