> How do you divide one set by another set? By defining it as the inverse of multiplication, of course! (Assuming the inverse exists.) A number n can be defin

> How do you divide one set by another set? By defining it as the inverse of multiplication, of course! (Assuming the inverse exists.) A number n can be defined as the class of all sets that are 1-to-1 with { x1, ..., xn }, where xi are distinct "things". Then, x * y is the class of all sets that are 1-to-1 with the cross-product of any element of x with any element of y. (2/3 is the wrong answer according to this definition; the right answer is any n > 0 or aleph 0).