Unit 8 · Detecting Reasoning Errors
Monotremes — Conditional Logic Error
Lesson 13 of 34
About this lesson
Jack restates the rule directly. Amelia flips it around and negates both sides — that's the contrapositive, and it's always just as valid as the original. Both are right, and understanding why is one of the most powerful tools in logical reasoning.
Chapters
Question
Monotremes are the only type of mammal that lay eggs.
Jack said: "If you see a mammal laying an egg, you know it must be a monotreme."
Amelia said: "And if you see an animal laying an egg, and you know it isn't a monotreme, then it can't be a mammal."
If the information in the box is true, whose reasoning is correct?
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