Brandon drove from Town Q to Town R which was 328 km away. He started from Town Q at an average speed of 75 km/h. He maintained this speed for 2 h before increasing it by 4 km/h for the rest of the journey to Town R.
- How long did he take to complete the whole journey?
- What was his average speed from Town Q to Town R?
(a)
Distance of 1st part of the journey
= 2 x 75
= 150 km
New speed for rest of the journey
= 75 + 4
= 79 km / h
Remaining distance for rest of the journey
= 328 - 150
= 178 km
Time taken for rest of the journey
= 178 ÷ 79
= 2 h
Total time taken
= 2 + 2
= 4 h
(b)
Average speed of the whole journey
= 328 ÷ 4
= 82 km
Answer(s): (a) 4 h; (b) 82km/h