Diana and Liam started running together along a cross country track. When Liam completed the track in 21 minutes, Diana had run only
35 of the track. Diana’s average speed was 96 m/min slower than Liam’s.
- How long was the cross country track in m?
- Find Diana’s average speed in m/min.
(a)
When Liam completed the track:
Liam's distance = 5 u
Diana's distance = 3 u
Extra distance covered by Liam
= 5 u - 3 u
= 2 u
2 u = 96 x 21
2 u = 2016
1 u = 2016 ÷ 2 = 1008
Distance of the cross country track
= 5 u
= 5 x 1008
= 5040 m
(b)
Liam's speed
= 5040 ÷ 21
= 240 m/min
Diana's speed
= 240 - 96
= 144 m/min
Answer(s): (a) 5040 m; (b) 144 m/min