Q7 of 70 Page 19

A hollow garden roller 63 cm wide with a girth of 440 cm, is made of 4 cm thick iron. Find the volume of the iron.


Given,


Width of hollow cylinder = 63 cm


Girth (perimeter) = 440 cm


Let external radius of cylinder = R cm


So, 2πr = 440


= R =


= inner radius = outer radius – thickness = 70 – 4 = 66 cm


∴ volume of iron = π( R2-r2)h =


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