Marion and Rael started running together along a cross country track. When Rael completed the track in 21 minutes, Marion had run only
59 of the track. Marion’s average speed was 112 m/min slower than Rael’s.
- How long was the cross country track in m?
- Find Marion’s average speed in m/min.
(a)
When Rael completed the track:
Rael's distance = 9 u
Marion's distance = 5 u
Extra distance covered by Rael
= 9 u - 5 u
= 4 u
4 u = 112 x 21
4 u = 2352
1 u = 2352 ÷ 4 = 588
Distance of the cross country track
= 9 u
= 9 x 588
= 5292 m
(b)
Rael's speed
= 5292 ÷ 21
= 252 m/min
Marion's speed
= 252 - 112
= 140 m/min
Answer(s): (a) 5292 m; (b) 140 m/min