Betty and George started running together along a cross country track. When George completed the track in 45 minutes, Betty had run only
35 of the track. Betty’s average speed was 98 m/min slower than George’s.
- How long was the cross country track in m?
- Find Betty’s average speed in m/min.
(a)
When George completed the track:
George's distance = 5 u
Betty's distance = 3 u
Extra distance covered by George
= 5 u - 3 u
= 2 u
2 u = 98 x 45
2 u = 4410
1 u = 4410 ÷ 2 = 2205
Distance of the cross country track
= 5 u
= 5 x 2205
= 11025 m
(b)
George's speed
= 11025 ÷ 45
= 245 m/min
Betty's speed
= 245 - 98
= 147 m/min
Answer(s): (a) 11025 m; (b) 147 m/min