Vaidev drove from Town Q to Town R which was 356 km away. He started from Town Q at an average speed of 73 km/h. He maintained this speed for 3 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
= 3 x 73
= 219 km
New speed for rest of the journey
= 73 + 5
= 78 km / h
Remaining distance for rest of the journey
= 356 - 219
= 137 km
Time taken for rest of the journey
= 137 ÷ 78
= 1 h
Total time taken
= 3 + 1
= 4 h
(b)
Average speed of the whole journey
= 356 ÷ 4
= 89 km
Answer(s): (a) 4 h; (b) 89km/h