Can someone help me find the last two blank numbers, everything else is right. Have to use formulas.

\begin{tabular}{|c|c|c|c|c|c|c|} \hline & A & B & C & D & E & F \\ \hline \multicolumn{7}{|c|}{1} \\ \hline 2 & Required: & & & & & \\ \hline 3 & \multirow{2}{*}{\multicolumn{5}{|c|}{ Solve for the missing amounts for the following separate cases. }} & \\ \hline 4 & & & & & & \\ \hline 5 & Case & Salespriceperunit & Variablecostsperunit & Contributionmarginperunit & Contributionmarginratio & \\ \hline 6 & 1 & $20 & $16 & $4 & 20% & \\ \hline 7 & 2 & 40 & 30 & 10 & 25% & \\ \hline 8 & 3 & & & 50 & 20% & \\ \hline 9 & & & & & & \\ \hline \end{tabular}