Gabriel drove from Town R to Town S which was 720 km away. He started from Town R at an average speed of 80 km/h. He maintained this speed for 3 h before increasing it by 4 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
= 3 x 80
= 240 km
New speed for rest of the journey
= 80 + 4
= 84 km / h
Remaining distance for rest of the journey
= 720 - 240
= 480 km
Time taken for rest of the journey
= 480 ÷ 84
= 5 h
Total time taken
= 3 + 5
= 8 h
(b)
Average speed of the whole journey
= 720 ÷ 8
= 90 km
Answer(s): (a) 8 h; (b) 90km/h