Min and Vaidev started running together along a cross country track. When Vaidev completed the track in 21 minutes, Min had run only
38 of the track. Min’s average speed was 105 m/min slower than Vaidev’s.
- How long was the cross country track in m?
- Find Min’s average speed in m/min.
(a)
When Vaidev completed the track:
Vaidev's distance = 8 u
Min's distance = 3 u
Extra distance covered by Vaidev
= 8 u - 3 u
= 5 u
5 u = 105 x 21
5 u = 2205
1 u = 2205 ÷ 5 = 441
Distance of the cross country track
= 8 u
= 8 x 441
= 3528 m
(b)
Vaidev's speed
= 3528 ÷ 21
= 168 m/min
Min's speed
= 168 - 105
= 63 m/min
Answer(s): (a) 3528 m; (b) 63 m/min