Kylie and Perry started running together along a cross country track. When Perry completed the track in 38 minutes, Kylie had run only
59 of the track. Kylie’s average speed was 100 m/min slower than Perry’s.
- How long was the cross country track in m?
- Find Kylie’s average speed in m/min.
(a)
When Perry completed the track:
Perry's distance = 9 u
Kylie's distance = 5 u
Extra distance covered by Perry
= 9 u - 5 u
= 4 u
4 u = 100 x 38
4 u = 3800
1 u = 3800 ÷ 4 = 950
Distance of the cross country track
= 9 u
= 9 x 950
= 8550 m
(b)
Perry's speed
= 8550 ÷ 38
= 225 m/min
Kylie's speed
= 225 - 100
= 125 m/min
Answer(s): (a) 8550 m; (b) 125 m/min