If the radius of a circle is increased by 10 % then prove the volume will increase by 33.1%

So

if increase by 10%, that means times 1.1

sub 1.1r for r in

V = (4/3) pir³

so

nV = (4/3) pir³

nV = (4/3) pi (1.1r) ³

nV = (4/3) pi1.331r³

nv = ((4/3) pir³) 1.331

V = (4/3) pir³

nV = (V) 1.331

x times 1.331 is about a 33% increase