Diana and Bobby started running together along a cross country track. When Bobby completed the track in 26 minutes, Diana had run only
59 of the track. Diana’s average speed was 100 m/min slower than Bobby’s.
- How long was the cross country track in m?
- Find Diana’s average speed in m/min.
(a)
When Bobby completed the track:
Bobby's distance = 9 u
Diana's distance = 5 u
Extra distance covered by Bobby
= 9 u - 5 u
= 4 u
4 u = 100 x 26
4 u = 2600
1 u = 2600 ÷ 4 = 650
Distance of the cross country track
= 9 u
= 9 x 650
= 5850 m
(b)
Bobby's speed
= 5850 ÷ 26
= 225 m/min
Diana's speed
= 225 - 100
= 125 m/min
Answer(s): (a) 5850 m; (b) 125 m/min