Syllogisms and Deductions Flashcards
6 cards from real CCAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Syllogisms and Deductions flashcards as text
If A > B and B > C, which of the following must be true?
Answer: A > C
By transitivity of inequality: A > B and B > C implies A > C.
Premises: All X are Y. No Z are Y. Conclusion: No X are Z. Is this valid?
Answer: Valid
X is inside Y. Z has no overlap with Y. Since X is entirely in Y, and Z has no overlap with Y, X and Z cannot overlap.
Premises: Either the meeting is on Monday or Tuesday. The meeting is not on Monday. Conclusion: The meeting is on Tuesday.
Answer: Valid — disjunctive syllogism
Disjunctive syllogism: (P or Q); not P; therefore Q. Valid form.
Premises: If Maria studies, she passes. Maria did not pass. Conclusion: Maria did not study.
Answer: Valid — modus tollens
Modus tollens: If P then Q; not Q; therefore not P. Studies implies passes; did not pass; therefore did not study.
Premises: All squares are rectangles. Shape X is not a rectangle. Conclusion: Shape X is not a square.
Answer: Valid
Contrapositive: not-rectangle implies not-square. Shape X is not a rectangle, so it cannot be a square.
Premises: Some students are athletes. Some athletes are musicians. Conclusion: Some students are musicians. Is this valid?
Answer: Invalid
Invalid. The students who are athletes and the athletes who are musicians could be completely different people.