4*3*2*1 = 24.
The actual numbers are
1234
1243
1342
1324
1423
1432
2134
2143
2314
2314
2413
2431
3124
3142
3234
3243
3413
3431
4321
4312
4213
4231
4123
4132
99999
There are 3,265,920 numbers that can be formed using all the digits. The answer to the question will depend on which one of these.
15 of them.
27
Possible solutions - using your rules are:- 11,13,17,31,33,37,71,73 &77
99999
There are 3,265,920 numbers that can be formed using all the digits. The answer to the question will depend on which one of these.
There are 60480 numbers.
There are 4^6 = 4096 such numbers.
8.
If the digits are all different then 18. Otherwise, 192.
There are 900 of them.
15 of them.
Assuming each of the given digits can be used only once, the answer is 24. If not, the answer is infinity.
27
Possible solutions - using your rules are:- 11,13,17,31,33,37,71,73 &77
6