Julie and Xavier started running together along a cross country track. When Xavier completed the track in 40 minutes, Julie had run only
13 of the track. Julie’s average speed was 108 m/min slower than Xavier’s.
- How long was the cross country track in m?
- Find Julie’s average speed in m/min.
(a)
When Xavier completed the track:
Xavier's distance = 3 u
Julie's distance = 1 u
Extra distance covered by Xavier
= 3 u - 1 u
= 2 u
2 u = 108 x 40
2 u = 4320
1 u = 4320 ÷ 2 = 2160
Distance of the cross country track
= 3 u
= 3 x 2160
= 6480 m
(b)
Xavier's speed
= 6480 ÷ 40
= 162 m/min
Julie's speed
= 162 - 108
= 54 m/min
Answer(s): (a) 6480 m; (b) 54 m/min