Question

How many one-to-one correspondences are there between the set {1,2,3} and the set {4,5,6}?​

Answer 1

Answer: 6 * 5 * 4 * 3 * 2 * 1, i.e. 6! or 720. Of course, since both sets have the same number of elements, you can't have one-to-one without being onto, aka a surjection, so “one to one correspondence” is the right term

Step-by-step explanation: an educated guess but hope this helps