A Firm of Four Departments Has the Following Trip Matrix

A firm of four departments has the following trip matrix and current block plan of all departments:
$$\begin{array} { | c | c | c | c | c | } \hline \begin{array} { c } \text { Dept. } \\\text { Name }\end{array} & \mathrm { A } & \mathrm { B } & \mathrm { C } & \mathrm { D } \\\hline \mathrm { A } & - - & 14 & 6 & 9 \\\hline \mathrm { B } & & - - & 7 & 16 \\\hline \mathrm { C } & & & & 2 \\\hline \mathrm { D } & & & & \cdots \\\hline\end{array}$$
$$\begin{array} { | c | c | } \hline \mathrm { A } & \mathrm { B } \\\hline \mathrm { D } & \mathrm { C } \\\hline\end{array}$$
a.What is the load-distance score for the current layout? (Assume rectilinear distance and that the distance between departments A and B is one unit of distance.)
b.What would be the load-distance score for the following layout?
$$\begin{array} { | c | c | } \hline \mathrm { A } & \mathrm { C } \\\hline \mathrm { D } & \mathrm { B } \\\hline\end{array}$$