$[$Using C$-$B$-$M$].$ Calculate the EIy at A and D$.$ The gross moment of Inertia of $BC$ is thrice that of $AB$ and $CD.$

Take $E=70$GPa.

Ans: $EI{y}_A=24\mathrm{.}136$darr;$EI{y}_D=62\mathrm{.}132$uarr;