Lucy and Ivan started running together along a cross country track. When Ivan completed the track in 31 minutes, Lucy had run only
13 of the track. Lucy’s average speed was 110 m/min slower than Ivan’s.
- How long was the cross country track in m?
- Find Lucy’s average speed in m/min.
(a)
When Ivan completed the track:
Ivan's distance = 3 u
Lucy's distance = 1 u
Extra distance covered by Ivan
= 3 u - 1 u
= 2 u
2 u = 110 x 31
2 u = 3410
1 u = 3410 ÷ 2 = 1705
Distance of the cross country track
= 3 u
= 3 x 1705
= 5115 m
(b)
Ivan's speed
= 5115 ÷ 31
= 165 m/min
Lucy's speed
= 165 - 110
= 55 m/min
Answer(s): (a) 5115 m; (b) 55 m/min