Will drove from Town R to Town S which was 426 km away. He started from Town R at an average speed of 61 km/h. He maintained this speed for 2 h before increasing it by 5 km/h for the rest of the journey to Town S.
- How long did he take to complete the whole journey?
- What was his average speed from Town R to Town S?
(a)
Distance of 1st part of the journey
= 2 x 61
= 122 km
New speed for rest of the journey
= 61 + 5
= 66 km / h
Remaining distance for rest of the journey
= 426 - 122
= 304 km
Time taken for rest of the journey
= 304 ÷ 66
= 4 h
Total time taken
= 2 + 4
= 6 h
(b)
Average speed of the whole journey
= 426 ÷ 6
= 71 km
Answer(s): (a) 6 h; (b) 71km/h