Elyse and Japheth started running together along a cross country track. When Japheth completed the track in 39 minutes, Elyse had run only
47 of the track. Elyse’s average speed was 108 m/min slower than Japheth’s.
- How long was the cross country track in m?
- Find Elyse’s average speed in m/min.
(a)
When Japheth completed the track:
Japheth's distance = 7 u
Elyse's distance = 4 u
Extra distance covered by Japheth
= 7 u - 4 u
= 3 u
3 u = 108 x 39
3 u = 4212
1 u = 4212 ÷ 3 = 1404
Distance of the cross country track
= 7 u
= 7 x 1404
= 9828 m
(b)
Japheth's speed
= 9828 ÷ 39
= 252 m/min
Elyse's speed
= 252 - 108
= 144 m/min
Answer(s): (a) 9828 m; (b) 144 m/min