Elijah drove from Town J to Town K which was 518 km away. He started from Town J at an average speed of 67 km/h. He maintained this speed for 3 h before increasing it by 4 km/h for the rest of the journey to Town K.
- How long did he take to complete the whole journey?
- What was his average speed from Town J to Town K?
(a)
Distance of 1st part of the journey
= 3 x 67
= 201 km
New speed for rest of the journey
= 67 + 4
= 71 km / h
Remaining distance for rest of the journey
= 518 - 201
= 317 km
Time taken for rest of the journey
= 317 ÷ 71
= 4 h
Total time taken
= 3 + 4
= 7 h
(b)
Average speed of the whole journey
= 518 ÷ 7
= 74 km
Answer(s): (a) 7 h; (b) 74km/h