小糊涂Slow Chinese Stories | Chinese Listening Practice HSK 3 

Haha, the math problem is good !! 🙂 I have also figured out the linguistic problem related to 问道. When 道 is used after a verb related to verbal expression, such as 说道, 喊道, etc., then it means that we are dealing with a direct quotation (exact wording). In print, this kind of quotation is always shown in quote marks. I have not seen this usage of 道 explained in any dictionary or grammar text, but I have found that it is commonly used this way.