Ivan drove from Town K to Town L which was 576 km away. He started from Town K at an average speed of 66 km/h. He maintained this speed for 3 h before increasing it by 10 km/h for the rest of the journey to Town L.
- How long did he take to complete the whole journey?
- What was his average speed from Town K to Town L?
(a)
Distance of 1st part of the journey
= 3 x 66
= 198 km
New speed for rest of the journey
= 66 + 10
= 76 km / h
Remaining distance for rest of the journey
= 576 - 198
= 378 km
Time taken for rest of the journey
= 378 ÷ 76
= 5 h
Total time taken
= 3 + 5
= 8 h
(b)
Average speed of the whole journey
= 576 ÷ 8
= 72 km
Answer(s): (a) 8 h; (b) 72km/h