Ivory and Michael started running together along a cross country track. When Michael completed the track in 30 minutes, Ivory had run only
49 of the track. Ivory’s average speed was 100 m/min slower than Michael’s.
- How long was the cross country track in m?
- Find Ivory’s average speed in m/min.
(a)
When Michael completed the track:
Michael's distance = 9 u
Ivory's distance = 4 u
Extra distance covered by Michael
= 9 u - 4 u
= 5 u
5 u = 100 x 30
5 u = 3000
1 u = 3000 ÷ 5 = 600
Distance of the cross country track
= 9 u
= 9 x 600
= 5400 m
(b)
Michael's speed
= 5400 ÷ 30
= 180 m/min
Ivory's speed
= 180 - 100
= 80 m/min
Answer(s): (a) 5400 m; (b) 80 m/min