Final answer:
The information needed to determine the digit that the letter b represents in the addition problem is missing. Without the specific math puzzle or context, it is not possible to provide an accurate answer.
Step-by-step explanation:
The question seems to be from a math puzzle or alphanumeric riddle where letters stand for digits in an addition problem. However, the information provided does not contain the specifics of the addition problem. Due to insufficient details, determining what digit the letter b represents cannot be accurately provided without the actual numeric puzzle or additional context. Typically, such puzzles require careful reasoning and understanding of place values in addition to determine the value of each letter.
Without the exact problem, one cannot use the method of simple addition and reasoning based on place value and the properties of numbers to find the solution. The necessary clue or the complete addition puzzle is missing, so we cannot proceed with a solution.