Emily and Harry started running together along a cross country track. When Harry completed the track in 31 minutes, Emily had run only
59 of the track. Emily’s average speed was 112 m/min slower than Harry’s.
- How long was the cross country track in m?
- Find Emily’s average speed in m/min.
(a)
When Harry completed the track:
Harry's distance = 9 u
Emily's distance = 5 u
Extra distance covered by Harry
= 9 u - 5 u
= 4 u
4 u = 112 x 31
4 u = 3472
1 u = 3472 ÷ 4 = 868
Distance of the cross country track
= 9 u
= 9 x 868
= 7812 m
(b)
Harry's speed
= 7812 ÷ 31
= 252 m/min
Emily's speed
= 252 - 112
= 140 m/min
Answer(s): (a) 7812 m; (b) 140 m/min