Ahmad drove from Town Q to Town R which was 380 km away. He started from Town Q at an average speed of 67 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 67
= 134 km
New speed for rest of the journey
= 67 + 4
= 71 km / h
Remaining distance for rest of the journey
= 380 - 134
= 246 km
Time taken for rest of the journey
= 246 ÷ 71
= 3 h
Total time taken
= 2 + 3
= 5 h
(b)
Average speed of the whole journey
= 380 ÷ 5
= 76 km
Answer(s): (a) 5 h; (b) 76km/h