Betty and Warren started running together along a cross country track. When Warren completed the track in 42 minutes, Betty had run only
47 of the track. Betty’s average speed was 102 m/min slower than Warren’s.
- How long was the cross country track in m?
- Find Betty’s average speed in m/min.
(a)
When Warren completed the track:
Warren's distance = 7 u
Betty's distance = 4 u
Extra distance covered by Warren
= 7 u - 4 u
= 3 u
3 u = 102 x 42
3 u = 4284
1 u = 4284 ÷ 3 = 1428
Distance of the cross country track
= 7 u
= 7 x 1428
= 9996 m
(b)
Warren's speed
= 9996 ÷ 42
= 238 m/min
Betty's speed
= 238 - 102
= 136 m/min
Answer(s): (a) 9996 m; (b) 136 m/min