Cindy and Sean started running together along a cross country track. When Sean completed the track in 43 minutes, Cindy had run only
13 of the track. Cindy’s average speed was 108 m/min slower than Sean’s.
- How long was the cross country track in m?
- Find Cindy’s average speed in m/min.
(a)
When Sean completed the track:
Sean's distance = 3 u
Cindy's distance = 1 u
Extra distance covered by Sean
= 3 u - 1 u
= 2 u
2 u = 108 x 43
2 u = 4644
1 u = 4644 ÷ 2 = 2322
Distance of the cross country track
= 3 u
= 3 x 2322
= 6966 m
(b)
Sean's speed
= 6966 ÷ 43
= 162 m/min
Cindy's speed
= 162 - 108
= 54 m/min
Answer(s): (a) 6966 m; (b) 54 m/min