Question

Kenneth and Marshall started cycling from the same starting point along a
track. Both started cycling at the same time and they did not change their
speeds throughout.
Kenneth reached the end of the track in 2 hours: Marshall covered only 4/5 of the track in that time. Given that Kenneth's
average speed was 2 km/h faster than Marshall, find the length of the track.

Answer 1

If Kenneth's speed is k km/hr, then since distance = speed * time,
4/5 * 2k = 2(k-2)
k = 10 km/hr
and the track is 20 km

check: Marshall's speed is 10-2 = 8 km/hr
2*8 = 16 = 4/5 of the 30 km