Betty and Tim started running together along a cross country track. When Tim completed the track in 43 minutes, Betty had run only
49 of the track. Betty’s average speed was 115 m/min slower than Tim’s.
- How long was the cross country track in m?
- Find Betty’s average speed in m/min.
(a)
When Tim completed the track:
Tim's distance = 9 u
Betty's distance = 4 u
Extra distance covered by Tim
= 9 u - 4 u
= 5 u
5 u = 115 x 43
5 u = 4945
1 u = 4945 ÷ 5 = 989
Distance of the cross country track
= 9 u
= 9 x 989
= 8901 m
(b)
Tim's speed
= 8901 ÷ 43
= 207 m/min
Betty's speed
= 207 - 115
= 92 m/min
Answer(s): (a) 8901 m; (b) 92 m/min