She wants an equal amount of lotion and hand soap, if you do 48 divided by 16 you get 3 and if you do 64 divided by 16 you get 4 so if she wants equal she can put 3 in each box. Finally if you do 48 divided by 3 you get 16 and if you divide 64 by 3 you get 21.3 if you want equal you must go with 16.