987,653
The greatest 4-digit number with no repeated digits is... 9876
987,654
9876543
98765
987653
The greatest 4-digit number with no repeated digits is... 9876
98,764
It is possible to create a 3-digit number, without repeated digits so the probability is 1.
757
987,654
987653
98,764
9876543.
98,764
987654
98765
9876543