Gabby and Charlie started running together along a cross country track. When Charlie completed the track in 28 minutes, Gabby had run only
35 of the track. Gabby’s average speed was 100 m/min slower than Charlie’s.
- How long was the cross country track in m?
- Find Gabby’s average speed in m/min.
(a)
When Charlie completed the track:
Charlie's distance = 5 u
Gabby's distance = 3 u
Extra distance covered by Charlie
= 5 u - 3 u
= 2 u
2 u = 100 x 28
2 u = 2800
1 u = 2800 ÷ 2 = 1400
Distance of the cross country track
= 5 u
= 5 x 1400
= 7000 m
(b)
Charlie's speed
= 7000 ÷ 28
= 250 m/min
Gabby's speed
= 250 - 100
= 150 m/min
Answer(s): (a) 7000 m; (b) 150 m/min