Try the math, this is a good problem to work through. The position of the 5 doesn't impact the search space like that. 10% of the 10 digit numbers start with a

Try the math, this is a good problem to work through. The position of the 5 doesn't impact the search space like that. 10% of the 10 digit numbers start with a 5. 10% of the 10 digit numbers end with a 5. 5... in your example shouldn't be 1%.