Usha and Riordan started running together along a cross country track. When Riordan completed the track in 20 minutes, Usha had run only
59 of the track. Usha’s average speed was 104 m/min slower than Riordan’s.
- How long was the cross country track in m?
- Find Usha’s average speed in m/min.
(a)
When Riordan completed the track:
Riordan's distance = 9 u
Usha's distance = 5 u
Extra distance covered by Riordan
= 9 u - 5 u
= 4 u
4 u = 104 x 20
4 u = 2080
1 u = 2080 ÷ 4 = 520
Distance of the cross country track
= 9 u
= 9 x 520
= 4680 m
(b)
Riordan's speed
= 4680 ÷ 20
= 234 m/min
Usha's speed
= 234 - 104
= 130 m/min
Answer(s): (a) 4680 m; (b) 130 m/min