| 0 | 0 | $\times$ | 0 |
| 0 | $\times$ | 0 | $\times$ |
| 0 | 0 | 0 | 0 |
| $\times$ | 0 | 0 | 0 |
5. A total of 12 noughts and 4 crosses are arranged in 4 rows of 4 . One such arrangement is illustrated below.
\begin{center}
\begin{tabular}{ c c c c }
0 & 0 & $\times$ & 0 \\
0 & $\times$ & 0 & $\times$ \\
0 & 0 & 0 & 0 \\
$\times$ & 0 & 0 & 0 \\
\end{tabular}
\end{center}
(a) How many arrangements are there altogether?\\
(b) How many arrangements are there in which there is a cross in every row?\\
(c) How many arrangements are there in which there is a cross in every row and in every column?