Julie and Lee started running together along a cross country track. When Lee completed the track in 21 minutes, Julie had run only
59 of the track. Julie’s average speed was 112 m/min slower than Lee’s.
- How long was the cross country track in m?
- Find Julie’s average speed in m/min.
(a)
When Lee completed the track:
Lee's distance = 9 u
Julie's distance = 5 u
Extra distance covered by Lee
= 9 u - 5 u
= 4 u
4 u = 112 x 21
4 u = 2352
1 u = 2352 ÷ 4 = 588
Distance of the cross country track
= 9 u
= 9 x 588
= 5292 m
(b)
Lee's speed
= 5292 ÷ 21
= 252 m/min
Julie's speed
= 252 - 112
= 140 m/min
Answer(s): (a) 5292 m; (b) 140 m/min