Betty and Michael started running together along a cross country track. When Michael completed the track in 41 minutes, Betty had run only
47 of the track. Betty’s average speed was 114 m/min slower than Michael’s.
- How long was the cross country track in m?
- Find Betty’s average speed in m/min.
(a)
When Michael completed the track:
Michael's distance = 7 u
Betty's distance = 4 u
Extra distance covered by Michael
= 7 u - 4 u
= 3 u
3 u = 114 x 41
3 u = 4674
1 u = 4674 ÷ 3 = 1558
Distance of the cross country track
= 7 u
= 7 x 1558
= 10906 m
(b)
Michael's speed
= 10906 ÷ 41
= 266 m/min
Betty's speed
= 266 - 114
= 152 m/min
Answer(s): (a) 10906 m; (b) 152 m/min