Tina and Jack started running together along a cross country track. When Jack completed the track in 31 minutes, Tina had run only
35 of the track. Tina’s average speed was 102 m/min slower than Jack’s.
- How long was the cross country track in m?
- Find Tina’s average speed in m/min.
(a)
When Jack completed the track:
Jack's distance = 5 u
Tina's distance = 3 u
Extra distance covered by Jack
= 5 u - 3 u
= 2 u
2 u = 102 x 31
2 u = 3162
1 u = 3162 ÷ 2 = 1581
Distance of the cross country track
= 5 u
= 5 x 1581
= 7905 m
(b)
Jack's speed
= 7905 ÷ 31
= 255 m/min
Tina's speed
= 255 - 102
= 153 m/min
Answer(s): (a) 7905 m; (b) 153 m/min