Elyse and Bobby started running together along a cross country track. When Bobby completed the track in 39 minutes, Elyse had run only
13 of the track. Elyse’s average speed was 96 m/min slower than Bobby’s.
- How long was the cross country track in m?
- Find Elyse’s average speed in m/min.
(a)
When Bobby completed the track:
Bobby's distance = 3 u
Elyse's distance = 1 u
Extra distance covered by Bobby
= 3 u - 1 u
= 2 u
2 u = 96 x 39
2 u = 3744
1 u = 3744 ÷ 2 = 1872
Distance of the cross country track
= 3 u
= 3 x 1872
= 5616 m
(b)
Bobby's speed
= 5616 ÷ 39
= 144 m/min
Elyse's speed
= 144 - 96
= 48 m/min
Answer(s): (a) 5616 m; (b) 48 m/min