Erika and Fred started running together along a cross country track. When Fred completed the track in 37 minutes, Erika had run only
35 of the track. Erika’s average speed was 100 m/min slower than Fred’s.
- How long was the cross country track in m?
- Find Erika’s average speed in m/min.
(a)
When Fred completed the track:
Fred's distance = 5 u
Erika's distance = 3 u
Extra distance covered by Fred
= 5 u - 3 u
= 2 u
2 u = 100 x 37
2 u = 3700
1 u = 3700 ÷ 2 = 1850
Distance of the cross country track
= 5 u
= 5 x 1850
= 9250 m
(b)
Fred's speed
= 9250 ÷ 37
= 250 m/min
Erika's speed
= 250 - 100
= 150 m/min
Answer(s): (a) 9250 m; (b) 150 m/min