Irene and George started running together along a cross country track. When George completed the track in 35 minutes, Irene had run only
38 of the track. Irene’s average speed was 100 m/min slower than George’s.
- How long was the cross country track in m?
- Find Irene’s average speed in m/min.
(a)
When George completed the track:
George's distance = 8 u
Irene's distance = 3 u
Extra distance covered by George
= 8 u - 3 u
= 5 u
5 u = 100 x 35
5 u = 3500
1 u = 3500 ÷ 5 = 700
Distance of the cross country track
= 8 u
= 8 x 700
= 5600 m
(b)
George's speed
= 5600 ÷ 35
= 160 m/min
Irene's speed
= 160 - 100
= 60 m/min
Answer(s): (a) 5600 m; (b) 60 m/min