It is 120 if the digits cannot be repeated.
6*6*3 = 108 numbers.
94205 if digits are not to be repeated and 99999 if digits can be repeated
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
The largest ten digit number with no repeated digits is '9876543210'.
9x8x7x6x5x4x3x2x1 or 9! which equals 362880 possible combinations if no digits are repeated
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 .
(5 x 4 x 3 x 2) = 120 of them, if no digit can be repeated.If digits can be repeated in the same number, then 3,125numbers can be formed.
The largest number with no repeated digits is 9,876,543,210 although it is 10 digits long, the largest 3 digit number with no repeated digits is 987
1000000000 or, if negative numbers are permitted, then -9999999999
If you allow the number 000000000, then there are 109 or a billion numbers.