Answer
52 V
Work Step by Step
Energy E=Power$\times$Time$=75\,W\times60\,s=4500\,J$
Energy is related to capacitance and potential difference;
$E=\frac{1}{2}CV^{2}$
$\implies V=\sqrt {\frac{2E}{C}}=\sqrt {\frac{2\times4500\,J}{3.3\,F}}=52\,V$