Kimberly and Pierre started running together along a cross country track. When Pierre completed the track in 50 minutes, Kimberly had run only
59 of the track. Kimberly’s average speed was 112 m/min slower than Pierre’s.
- How long was the cross country track in m?
- Find Kimberly’s average speed in m/min.
(a)
When Pierre completed the track:
Pierre's distance = 9 u
Kimberly's distance = 5 u
Extra distance covered by Pierre
= 9 u - 5 u
= 4 u
4 u = 112 x 50
4 u = 5600
1 u = 5600 ÷ 4 = 1400
Distance of the cross country track
= 9 u
= 9 x 1400
= 12600 m
(b)
Pierre's speed
= 12600 ÷ 50
= 252 m/min
Kimberly's speed
= 252 - 112
= 140 m/min
Answer(s): (a) 12600 m; (b) 140 m/min