There are 4536 of them and I have neither the time nor the inclination to list them.
This assumes the starting digit is not 0. If 0 is allowed as the first digit, there will be 5040 such numbers.
Since each digit is used only once, this is a problem without replacement means that an outcome cannot be included more than once. In this case, the first event does affect the possibilities for the second event. These event are dependent. So the number could have any of these forms:
1_ _ _ , 2_ _ _ , 3_ _ _ , 4_ _ _ , 5_ _ _ , 6_ _ _ , 7_ _ _ , 8_ _ _ , 9_ _ _ .
There are 9 choices for the thousands digit: 1, 2, 3, 4, 5, 6, 7, 8, or 9.
After the thousands digit is chosen, 9 choices are left for the hundreds digit After the hundreds digit is chosen, 8 choices are left for the tens digit. After the tens digit is chosen, 7 choices are left for the units digit.
Then, we have (9 * 9 * 8 * 7) 4536 numbers.
9x8x7x6x5x4x3x2x1 or 9! which equals 362880 possible combinations if no digits are repeated
Assuming that repeated numbers are allowed, the number of possible combinations is given by 40 * 40 * 40 = 64000.If repeated numbers are not allowed, the number of possible combinations is given by 40 * 39 * 38 = 59280.
5 digit telephone numbers having at least one of their digits repeated is = total possible 5 digit telephone numbers - 5 digit telephone numbers without any digit being repeated. =(10*10*10*10*10)-(10*9*8*7*6) =100000-30240 =69760
625 if numbers can have leading 0s, 500 otherwise.
3897
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
9x8x7x6x5x4x3x2x1 or 9! which equals 362880 possible combinations if no digits are repeated
Assuming that repeated numbers are allowed, the number of possible combinations is given by 40 * 40 * 40 = 64000.If repeated numbers are not allowed, the number of possible combinations is given by 40 * 39 * 38 = 59280.
5 digit telephone numbers having at least one of their digits repeated is = total possible 5 digit telephone numbers - 5 digit telephone numbers without any digit being repeated. =(10*10*10*10*10)-(10*9*8*7*6) =100000-30240 =69760
There are 4 possible numbers if the digits are not repeated; 18 if they are. Those are 3-digit numbers, assuming that zero would not be a leading digit. If zero is allowed for a leading digit, then you can have 6 for the non repeated, and 27 if repetition.
625 if numbers can have leading 0s, 500 otherwise.
3897
If repeated digits are allowed, then the largest 12-digit number is 999,999,999,999 .If repeated digits are not allowed, then the largest 12-digit number is 989,898,989,898 .If the same digit can't be used more than once, then the largest possible number has only10 digits. The number is 9,876,543,210 .
9876
738 numbers
If a digit can be repeated there are 5 x 5 x 5 = 125 possible numbers If a digit cannot be repeated there are 5 x 4 x 3 = 60 possible numbers.
Assuming that leading zeros are not permitted (that is the lowest ten digit number is 1 000 000 000), then there are 4 500 000 000 possible even numbers