Marion and Ian started running together along a cross country track. When Ian completed the track in 38 minutes, Marion had run only
13 of the track. Marion’s average speed was 102 m/min slower than Ian’s.
- How long was the cross country track in m?
- Find Marion’s average speed in m/min.
(a)
When Ian completed the track:
Ian's distance = 3 u
Marion's distance = 1 u
Extra distance covered by Ian
= 3 u - 1 u
= 2 u
2 u = 102 x 38
2 u = 3876
1 u = 3876 ÷ 2 = 1938
Distance of the cross country track
= 3 u
= 3 x 1938
= 5814 m
(b)
Ian's speed
= 5814 ÷ 38
= 153 m/min
Marion's speed
= 153 - 102
= 51 m/min
Answer(s): (a) 5814 m; (b) 51 m/min