Rachel and Charlie started running together along a cross country track. When Charlie completed the track in 41 minutes, Rachel had run only
37 of the track. Rachel’s average speed was 108 m/min slower than Charlie’s.
- How long was the cross country track in m?
- Find Rachel’s average speed in m/min.
(a)
When Charlie completed the track:
Charlie's distance = 7 u
Rachel's distance = 3 u
Extra distance covered by Charlie
= 7 u - 3 u
= 4 u
4 u = 108 x 41
4 u = 4428
1 u = 4428 ÷ 4 = 1107
Distance of the cross country track
= 7 u
= 7 x 1107
= 7749 m
(b)
Charlie's speed
= 7749 ÷ 41
= 189 m/min
Rachel's speed
= 189 - 108
= 81 m/min
Answer(s): (a) 7749 m; (b) 81 m/min