\[
\begin{array}{|c|c|c|c|c|}
\hline
Part& ODE& PDE & Order & Linear/Non Linear \\
\hline
(a)&\checkmark & & 1 & Linear\\
\hline
(b)&\checkmark&&4&Linear \\
\hline
(c)&&\checkmark&2&Linear \\
\hline
(d)&\checkmark&&1&Non Linear \\
\hline
(e)&\checkmark&&2&Non Linear\\
\hline
\end{array}
\]