Answer
$$
\begin{aligned}
& F_C=600 \mathrm{~N} \\
& F_D=500 \mathrm{~N}
\end{aligned}
$$
Work Step by Step
$$
\begin{gathered}
\Sigma M_x=0 ; \quad F_D(0.4)+600(0.4)-F_C(0.4)-500(0.4)=0 \\
F_C-F_D=100 &(1)\\
\Sigma M_y=0 ; \quad 500(0.2)+600(0.2)-F_C(0.2)-F_D(0.2)=0 \\
F_C+F_D=1100 &(2)
\end{gathered}
$$
Solving Eqs. (1) and (2) yields:
$$
F_C=600 \mathrm{~N} \quad F_D=500 \mathrm{~N}
$$