answer: 32 sandwiches
explanation: well, if one sandwich uses one eighth of a pound of cheese, that means that eight eighths of a pound (i.e one whole pound) would make eight sandwiches. Since we know that there are four pounds of cheese altogether, we can use this ratio (8 sandwiches per every 1 pound of cheese) to calculate that he made 32 sandwiches (8 times 4).