Respuesta :

300 boxes
0.8 cup per box

300 * 0.8 cups = 240 cups

There are 16 cups in a gallon.

240/16 gal = 15 gal

Answer: 15

Your answer would be 15. I did the same work as the other guy, i just didn't write it down because i didn't want anyone thinking that i just copied him.
Hope This Helps!