In a crystalline solid,having formula $AB_2O_4$,oxide ions are arranged in cubic close packed lattice while cations A are present in tetrahedral voids and cations B are present in octahedral voids.What percentage of the tetrahedral voids is occupied by A and B?

Question

$\begin{array}{1 1}13.5\%,60\%\\12.5\%,50\%\\14.5\%,70\%\\17.5\%,80\%\end{array} $