Kathy and Lee started running together along a cross country track. When Lee completed the track in 22 minutes, Kathy had run only
37 of the track. Kathy’s average speed was 100 m/min slower than Lee’s.
- How long was the cross country track in m?
- Find Kathy’s average speed in m/min.
(a)
When Lee completed the track:
Lee's distance = 7 u
Kathy's distance = 3 u
Extra distance covered by Lee
= 7 u - 3 u
= 4 u
4 u = 100 x 22
4 u = 2200
1 u = 2200 ÷ 4 = 550
Distance of the cross country track
= 7 u
= 7 x 550
= 3850 m
(b)
Lee's speed
= 3850 ÷ 22
= 175 m/min
Kathy's speed
= 175 - 100
= 75 m/min
Answer(s): (a) 3850 m; (b) 75 m/min