Sabrina and Riordan started running together along a cross country track. When Riordan completed the track in 49 minutes, Sabrina had run only
13 of the track. Sabrina’s average speed was 102 m/min slower than Riordan’s.
- How long was the cross country track in m?
- Find Sabrina’s average speed in m/min.
(a)
When Riordan completed the track:
Riordan's distance = 3 u
Sabrina's distance = 1 u
Extra distance covered by Riordan
= 3 u - 1 u
= 2 u
2 u = 102 x 49
2 u = 4998
1 u = 4998 ÷ 2 = 2499
Distance of the cross country track
= 3 u
= 3 x 2499
= 7497 m
(b)
Riordan's speed
= 7497 ÷ 49
= 153 m/min
Sabrina's speed
= 153 - 102
= 51 m/min
Answer(s): (a) 7497 m; (b) 51 m/min