Statements: All squares are quadrilaterals. Some quadrilaterals are not squares. Conclusion: Some quadrilaterals are squares. This conclusion is
- A. valid
- B. invalid
- C. contradictory
- D. irrelevant
Explanation
If all squares are quadrilaterals and squares exist, then some quadrilaterals must be squares, which is a valid conversion of a universal affirmative into a particular one. The second premise adds that not every quadrilateral is a square, which is consistent rather than contradictory. Both statements can be true at once.
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