How many different combinations of four with six numbers if you can't repeat the numbers?

The answer depends on whether order matters. For example, would 1234 be considered the same as 4321. If order does not matter, there are only 15 combinations. This answer was obtained dividing the factorial 6 by the product of the factorial of 4 and the factorial of (6-4). In general, the amount of unordered combinations of x with y numbers is equal to y!/(x!(y-x)!). If order does matter, there are 360 combinations. This answer was obtained by diving the factorial of 6 by the factorial of (6-4). In general, the amount of ordered combinations of x with y numbers is equal to y!/((y-x)!).