How many numbers can you make using the digits 1 2 3 4?
1234 1243 1324 1342 1423 1432 2134 2143 2314 2341 2413 2431 3124
3142 3214 3241 3412 3421 4123 4132 4213 4231 4312 4321
If you can repeat digits, then there are 256 numbers
Without repetition, there are 24