Glen drove from Town P to Town Q which was 648 km away. He started from Town P at an average speed of 74 km/h. He maintained this speed for 4 h before increasing it by 5 km/h for the rest of the journey to Town Q.
- How long did he take to complete the whole journey?
- What was his average speed from Town P to Town Q?
(a)
Distance of 1st part of the journey
= 4 x 74
= 296 km
New speed for rest of the journey
= 74 + 5
= 79 km / h
Remaining distance for rest of the journey
= 648 - 296
= 352 km
Time taken for rest of the journey
= 352 ÷ 79
= 4 h
Total time taken
= 4 + 4
= 8 h
(b)
Average speed of the whole journey
= 648 ÷ 8
= 81 km
Answer(s): (a) 8 h; (b) 81km/h