Dana and Sam started running together along a cross country track. When Sam completed the track in 47 minutes, Dana had run only
49 of the track. Dana’s average speed was 115 m/min slower than Sam’s.
- How long was the cross country track in m?
- Find Dana’s average speed in m/min.
(a)
When Sam completed the track:
Sam's distance = 9 u
Dana's distance = 4 u
Extra distance covered by Sam
= 9 u - 4 u
= 5 u
5 u = 115 x 47
5 u = 5405
1 u = 5405 ÷ 5 = 1081
Distance of the cross country track
= 9 u
= 9 x 1081
= 9729 m
(b)
Sam's speed
= 9729 ÷ 47
= 207 m/min
Dana's speed
= 207 - 115
= 92 m/min
Answer(s): (a) 9729 m; (b) 92 m/min