Lucy and Rael started running together along a cross country track. When Rael completed the track in 27 minutes, Lucy had run only
13 of the track. Lucy’s average speed was 102 m/min slower than Rael’s.
- How long was the cross country track in m?
- Find Lucy’s average speed in m/min.
(a)
When Rael completed the track:
Rael's distance = 3 u
Lucy's distance = 1 u
Extra distance covered by Rael
= 3 u - 1 u
= 2 u
2 u = 102 x 27
2 u = 2754
1 u = 2754 ÷ 2 = 1377
Distance of the cross country track
= 3 u
= 3 x 1377
= 4131 m
(b)
Rael's speed
= 4131 ÷ 27
= 153 m/min
Lucy's speed
= 153 - 102
= 51 m/min
Answer(s): (a) 4131 m; (b) 51 m/min