Circumference of circles

Let w m be the width, r m be the inner radius
2π(r+w)-2πr=60
2πr-2πr+2πw=60
w=60/(2π)
=9.55(cor.to3sig.fig.)
Therefore, the width is 9.55m.

First , let the outer circumference of circular racing track's radius be R
and let the inner circumference of circular racing track's radius be r

2兀R - 2兀r = 60
2兀(R -r) = 60
R - r = 60 / (2兀)
R - r = 30兀

So, the width of the track is 30兀 , i.e. 9.5493 ( 5 sig.fig. )