1124 1224 1244
24680
24
There are 9*9*8*7 = 4536 of them.
4p3*3p1 equal to 72 ways
The answer is 3*3*2*1 = 18. If the leading digit is 0 it is not a 4-digit number.
24680
There are 840 4-digit combinations without repeating any digit in the combinations.
18, if leading 0s are disallowed.
24
93,876
There are 25 such numbers.
There are 9*9*8*7 = 4536 of them.
4p3*3p1 equal to 72 ways
120 5-digit numbers can be made with the numbers 12345.
468, 486, 648, 684, 846, 864.
The answer is 3*3*2*1 = 18. If the leading digit is 0 it is not a 4-digit number.
502 205 250 520 4 numbers. If a leading zero is allowed then you can have 052 and 025 for 6 numbers.