The difference between the external and internal curved surface areas of a 7 cm long cylindrical metallic pipe is 110 cm2 . If the pipe is made of 302.5 cm3 metal, then find the inner radius of the pipe.
(Use π = \(\frac{22}{7} \))
1
1.5 cm
2
1.6 cm
3
2.2 cm
4
1.8 cm