Ahmad drove from Town Z to Town A which was 525 km away. He started from Town Z at an average speed of 72 km/h. He maintained this speed for 2 h before increasing it by 4 km/h for the rest of the journey to Town A.
- How long did he take to complete the whole journey?
- What was his average speed from Town Z to Town A?
(a)
Distance of 1st part of the journey
= 2 x 72
= 144 km
New speed for rest of the journey
= 72 + 4
= 76 km / h
Remaining distance for rest of the journey
= 525 - 144
= 381 km
Time taken for rest of the journey
= 381 ÷ 76
= 5 h
Total time taken
= 2 + 5
= 7 h
(b)
Average speed of the whole journey
= 525 ÷ 7
= 75 km
Answer(s): (a) 7 h; (b) 75km/h