Let the radius of the inner circular path be r m. Therefore, the radius of the outer circular path =(r+5)m Perimeter of the outer circular path : Perimeter of the inner circular path = 23 : 22 ⇒
2π(r+5)
2πr
=
23
22
⇒
5
r
=
23
22
−1=
1
22
⇒=110m Therefore, diameter of inner circle =2×110=220m