1,680
÷ 400
= 4.2 Xian has completed 4.2 LAPS of the track,
400
x 14
= 5,600 So this is the total amount of yards in the track
5,600
- 1,680
=3,920 So this is how many yards are left for Xian to run
3,920
÷ 400
= 9.8 This is how many laps Xian has to run
4.2 + 9.8 = 14
so estimating how many laps Xian has run compared to how many he has left, he has completed 30% of the track.