Volume of large box = 5832 in^3 Volume of shoe box = 12*6*5=360 in^3
Maximum number of shoe boxes that might fit in the large box = 5832/360 = 16.2, or 16.
However, we have to verify the dimensions to make sure each side fits. For example, if the large box is 18x18x18=5832 in^3, then we can only fit, along each dimension: 18/12=1.5 => 1 (6 inches remaining) 18/6=3 => 3 (0 inches remaining) 18/5=3.6 => 3 (3 inches remaining) That make 9 boxes. However, we still have a gap of 6 inches that we can fit shoe boxes vertically, i.e. 6/6=1 row 18/12=1 row 18/5 = 3 rows That will fit 3 more boxes for a total of 9+3=12 boxes (instead of 16 boxes).
So 16 is the MAXIMUM number of boxes (according to volume). The actual number of boxes will depend on the dimensions of the large box. 18x18x18 was given just as an example.
If further explanations are needed, please post in comments.
Since Garrett and Carter bought popcorn and drinks, we have to figure out how much money is 1 drink and 1 popcorn. I figured the best way is to figure out half of $12.50 because 2 drinks and 2 popcorn cost that amount of money. You divide $12.50 by 2 to figure out half of that amount. The quotient equals to $6.25.