A horse racecourse is in the form of an annular ring whose outer and inner circumferences are 748 m and 396 m, respectively. The width (in m) of the racecourse is: (Take $$\pi=\frac{22}{7}$$)

A horse racecourse is in the form of an annular ring whose outer and inner circumferences are 748 m and 396 m.

Let's assume the radius of the outer part and the inner part is 'R' and 'r' respectively.

circumferences of outer part = $$2\times\pi\times R\ $$

$$748=2\times\frac{22}{7}\times R\ $$

$$748=\frac{44}{7}\times R\ $$

$$17=\frac{1}{7}\times R\ $$

R = 119 m

circumferences of inner part = $$2\times\pi\times r\ $$

$$396=2\times\frac{22}{7}\times r\ $$

$$396=\frac{44}{7}\times r\ $$

$$9=\frac{1}{7}\times r\ $$

r = 63 m

width (in m) of the racecourse = difference between the radius of outer and inner part

= 119-63

= 56 m