Opal and Billy started running together along a cross country track. When Billy completed the track in 32 minutes, Opal had run only
47 of the track. Opal’s average speed was 114 m/min slower than Billy’s.
- How long was the cross country track in m?
- Find Opal’s average speed in m/min.
(a)
When Billy completed the track:
Billy's distance = 7 u
Opal's distance = 4 u
Extra distance covered by Billy
= 7 u - 4 u
= 3 u
3 u = 114 x 32
3 u = 3648
1 u = 3648 ÷ 3 = 1216
Distance of the cross country track
= 7 u
= 7 x 1216
= 8512 m
(b)
Billy's speed
= 8512 ÷ 32
= 266 m/min
Opal's speed
= 266 - 114
= 152 m/min
Answer(s): (a) 8512 m; (b) 152 m/min