Mary and Owen started running together along a cross country track. When Owen completed the track in 29 minutes, Mary had run only
59 of the track. Mary’s average speed was 112 m/min slower than Owen’s.
- How long was the cross country track in m?
- Find Mary’s average speed in m/min.
(a)
When Owen completed the track:
Owen's distance = 9 u
Mary's distance = 5 u
Extra distance covered by Owen
= 9 u - 5 u
= 4 u
4 u = 112 x 29
4 u = 3248
1 u = 3248 ÷ 4 = 812
Distance of the cross country track
= 9 u
= 9 x 812
= 7308 m
(b)
Owen's speed
= 7308 ÷ 29
= 252 m/min
Mary's speed
= 252 - 112
= 140 m/min
Answer(s): (a) 7308 m; (b) 140 m/min