Min and Billy started running together along a cross country track. When Billy completed the track in 25 minutes, Min had run only
13 of the track. Min’s average speed was 108 m/min slower than Billy’s.
- How long was the cross country track in m?
- Find Min’s average speed in m/min.
(a)
When Billy completed the track:
Billy's distance = 3 u
Min's distance = 1 u
Extra distance covered by Billy
= 3 u - 1 u
= 2 u
2 u = 108 x 25
2 u = 2700
1 u = 2700 ÷ 2 = 1350
Distance of the cross country track
= 3 u
= 3 x 1350
= 4050 m
(b)
Billy's speed
= 4050 ÷ 25
= 162 m/min
Min's speed
= 162 - 108
= 54 m/min
Answer(s): (a) 4050 m; (b) 54 m/min