Shiyun and Ian started running together along a cross country track. When Ian completed the track in 30 minutes, Shiyun had run only
59 of the track. Shiyun’s average speed was 100 m/min slower than Ian’s.
- How long was the cross country track in m?
- Find Shiyun’s average speed in m/min.
(a)
When Ian completed the track:
Ian's distance = 9 u
Shiyun's distance = 5 u
Extra distance covered by Ian
= 9 u - 5 u
= 4 u
4 u = 100 x 30
4 u = 3000
1 u = 3000 ÷ 4 = 750
Distance of the cross country track
= 9 u
= 9 x 750
= 6750 m
(b)
Ian's speed
= 6750 ÷ 30
= 225 m/min
Shiyun's speed
= 225 - 100
= 125 m/min
Answer(s): (a) 6750 m; (b) 125 m/min