Tiffany and Daniel started running together along a cross country track. When Daniel completed the track in 21 minutes, Tiffany had run only
13 of the track. Tiffany’s average speed was 108 m/min slower than Daniel’s.
- How long was the cross country track in m?
- Find Tiffany’s average speed in m/min.
(a)
When Daniel completed the track:
Daniel's distance = 3 u
Tiffany's distance = 1 u
Extra distance covered by Daniel
= 3 u - 1 u
= 2 u
2 u = 108 x 21
2 u = 2268
1 u = 2268 ÷ 2 = 1134
Distance of the cross country track
= 3 u
= 3 x 1134
= 3402 m
(b)
Daniel's speed
= 3402 ÷ 21
= 162 m/min
Tiffany's speed
= 162 - 108
= 54 m/min
Answer(s): (a) 3402 m; (b) 54 m/min