Answer
(a) $3.1\times10^{-9}\,C$
(b) $3.7\times10^{-8}\,J$
Work Step by Step
(a) Charge $q=CV=(\kappa C_{0})V=(2.6\times50\times10^{-12}\,F)24\,V$
$=3.1\times10^{-9}\,C$
(b) Energy $U=\frac{1}{2}CV^{2}=\frac{1}{2}\times(\kappa C_{0})\times V^{2}$
$=\frac{1}{2}\times2.6\times50\times10^{-12}\,F\times(24\,V)^{2}=3.7\times10^{-8}\,J$