Je complète un tableau de proportionnalité

Exemple
\(\begin{array}{|c|c|} \hline 2&12 \\ \hline 4&... \\ \hline \end{array}\)           Calcul :   `(4 \times 12)/2 = 24` .

Exercice

1.  \(\begin{array}{|c|c|} \hline 10&3 \\ \hline 4&... \\ \hline \end{array}\)

2. \(\begin{array}{|c|c|} \hline 100&2 \\ \hline 3&... \\ \hline \end{array}\)

\(\) c. \(\begin{array}{|c|c|} \hline 75&... \\ \hline 9&20 \\ \hline \end{array}\)

\(\) d. \(\begin{array}{|c|c|} \hline 33&... \\ \hline 8&63 \\ \hline \end{array}\)