Note before reading: Even though there are elements of logic found in this description, that does not mean that this question belongs in the Mathematics or Puzzling stack exchange. This is because my question focuses on the meaning of a phrase, not how I should determine the phrase’s truth value. Please carefully read what I’m asking for.
Suppose you have only two children, one named Alice and another named Bob. During one quiet evening, Alice and Bob walk up to you with no explanation, and Alice says, "One of us is a child of yours." Is Alice telling the truth?
I'm having a hard time answering this question because I'm not sure how I should interpret the statement "one of us is a child of yours." I've asked a few people this question, and about half of them say that Alice is not telling the truth because they interpret the statement "one of us is a child of yours" as "exactly one of us is a child of yours." The other half of people say that Alice is being truthful because they interpret "one of us is a child of yours" as "at least one of us is a child of yours." Which way should I interpret the statement "one of us is a child of yours”? Is more context needed? Is it too ambiguous?
When we come across statements like "Josh has five apples,” it is often implied that he has exactly five apples (i.e. the word “exactly” is implicit), so I was thinking that maybe "exactly one of us is a child of yours" is the way to go. Would that be right? (If it is, that would mean that Alice was wrong when she said “one of us is a child of yours.”)