$V = \dfrac{1}{3}\pi r^{2}h$

$\implies V \propto r^{2}$

$\implies V = (1.5)^{2} = 2.25 = (2.25-1)\times 100\% = 1.25\times 100\% = 125\%\Big\Uparrow$

$\implies V \propto r^{2}$

$\implies V = (1.5)^{2} = 2.25 = (2.25-1)\times 100\% = 1.25\times 100\% = 125\%\Big\Uparrow$