155390

Outer circumference=396m
2Ï€R=396m
2×22/7×R=396m
R=396×7/2×22
R=63m

Inner circumference=352
2Ï€r=352m
2×22/7×r=352m
r=352×7/2×22
r=56m
The width is
R-r
63-56=7m
The area of race track is
π(R×R-r×r)
=22/7×(63×63-56×56)
=22/7×(3969-3136)
=22/7×833
=2616m