Cindy and Bobby started running together along a cross country track. When Bobby completed the track in 43 minutes, Cindy had run only
13 of the track. Cindy’s average speed was 114 m/min slower than Bobby’s.
- How long was the cross country track in m?
- Find Cindy’s average speed in m/min.
(a)
When Bobby completed the track:
Bobby's distance = 3 u
Cindy's distance = 1 u
Extra distance covered by Bobby
= 3 u - 1 u
= 2 u
2 u = 114 x 43
2 u = 4902
1 u = 4902 ÷ 2 = 2451
Distance of the cross country track
= 3 u
= 3 x 2451
= 7353 m
(b)
Bobby's speed
= 7353 ÷ 43
= 171 m/min
Cindy's speed
= 171 - 114
= 57 m/min
Answer(s): (a) 7353 m; (b) 57 m/min