1000
99999
210 of them.
192 ways
500
744 digits.
6*5*4*3*2*1=720
36
10,000
99999
210 of them.
If the digits can be used more than once, then 900. If not, then 648.
192 ways
500
24
744 digits.
5040 different 4 digit numbers can be formed with the digits 123456789. This is assuming that no digits are repeated with each combination.
1 set