Mark drove from Town Q to Town R which was 504 km away. He started from Town Q at an average speed of 66 km/h. He maintained this speed for 2 h before increasing it by 5 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 66
= 132 km
New speed for rest of the journey
= 66 + 5
= 71 km / h
Remaining distance for rest of the journey
= 504 - 132
= 372 km
Time taken for rest of the journey
= 372 ÷ 71
= 5 h
Total time taken
= 2 + 5
= 7 h
(b)
Average speed of the whole journey
= 504 ÷ 7
= 72 km
Answer(s): (a) 7 h; (b) 72km/h