- The number has at least 2 digits.
- All digits of the number are in strictly ascending order, in base 10.
For completeness, let's also add: no leading zeros or duplicate digits.
For what value of N is the probability that a randomly chosen N-digit number is also an ascending number closest to .01, i.e. a 1% chance?
For this value of N, what is the exact probability the random number N digits long is ascending?