pr.probability – magnitude relation – MathOverflow

I have a question about magnitude relationship.

There is a sequence of 4 and 5. A is the number of numbers until sequence 45 first appears, and B is the number of numbers until sequence 55 first appears. I need to find magnitude relationship between the values of numbers A and B.

This is what I understand now: For example, if there is a sequence like 4444445554, A is 5 and B becomes 6. But I’m not sure what to find magnitude relationship between A and B… Could somebody help me?