My 6yo can answer this correctly, making all of your stated assumptions above. Edit: Clarification - I am in no way implying that someone who was confused by the math is dumb, everyone makes silly mistakes sometimes.
I think It’s only ambiguous to a machine. To a human, even in 2023, these are likely default assumptions for a question phrased as above, unless being overly pedantic or attempting to “get around” the puzzle.
If you ask a model - or a person - “what does 1+1 equal to?”,
it is also ambiguous, since we haven’t defined what “+” means, did not specify that we are dealing with natural numbers rather than eg elements in Z//2Z which could be similarly denoted.
