Natalie and Zeph started running together along a cross country track. When Zeph completed the track in 39 minutes, Natalie had run only
13 of the track. Natalie’s average speed was 110 m/min slower than Zeph’s.
- How long was the cross country track in m?
- Find Natalie’s average speed in m/min.
(a)
When Zeph completed the track:
Zeph's distance = 3 u
Natalie's distance = 1 u
Extra distance covered by Zeph
= 3 u - 1 u
= 2 u
2 u = 110 x 39
2 u = 4290
1 u = 4290 ÷ 2 = 2145
Distance of the cross country track
= 3 u
= 3 x 2145
= 6435 m
(b)
Zeph's speed
= 6435 ÷ 39
= 165 m/min
Natalie's speed
= 165 - 110
= 55 m/min
Answer(s): (a) 6435 m; (b) 55 m/min