Gwen and Henry started running together along a cross country track. When Henry completed the track in 50 minutes, Gwen had run only
47 of the track. Gwen’s average speed was 105 m/min slower than Henry’s.
- How long was the cross country track in m?
- Find Gwen’s average speed in m/min.
(a)
When Henry completed the track:
Henry's distance = 7 u
Gwen's distance = 4 u
Extra distance covered by Henry
= 7 u - 4 u
= 3 u
3 u = 105 x 50
3 u = 5250
1 u = 5250 ÷ 3 = 1750
Distance of the cross country track
= 7 u
= 7 x 1750
= 12250 m
(b)
Henry's speed
= 12250 ÷ 50
= 245 m/min
Gwen's speed
= 245 - 105
= 140 m/min
Answer(s): (a) 12250 m; (b) 140 m/min