Kathy and Sam started running together along a cross country track. When Sam completed the track in 39 minutes, Kathy had run only
35 of the track. Kathy’s average speed was 98 m/min slower than Sam’s.
- How long was the cross country track in m?
- Find Kathy’s average speed in m/min.
(a)
When Sam completed the track:
Sam's distance = 5 u
Kathy's distance = 3 u
Extra distance covered by Sam
= 5 u - 3 u
= 2 u
2 u = 98 x 39
2 u = 3822
1 u = 3822 ÷ 2 = 1911
Distance of the cross country track
= 5 u
= 5 x 1911
= 9555 m
(b)
Sam's speed
= 9555 ÷ 39
= 245 m/min
Kathy's speed
= 245 - 98
= 147 m/min
Answer(s): (a) 9555 m; (b) 147 m/min