Distance covered by circular wheel in 20 rotation = 3520 cm
∴ Distance covered in rotation = \(\frac{3520}{20}\) cm
= 176 cm
∴ Circumference of the wheel = 176 cm
∴ 2πr = 176
2 x \(\frac{-2}{6}\) x r = 176
r = \(\frac{176\times7}{2\times22}\)
r = 28 cm
Radius of the wheel = 28 cm