Read the set diagrams

Exercise and reference answers

Questions

1. Answer

   A

   Question

   Only the dot guarantees an existing object. Which conclusion must follow?

2. Answer

   B

   Question

   The rectangle is set C; circles are B and A. Which statement is false in this diagram?

3. Answer

   D

   Question

   The rectangle is B; the smallest circle is D. Only the dot guarantees existence. I: Some A are C. II: All D are B. III: All B are A. Which follow?

4. Answer

   D

   Question

   Choose exactly 3 of A–F. A requires B; C requires D; exactly one of B,E is chosen; F requires C; at least one of A,F is chosen. Which pair must be excluded?

5. Answer

   A

   Question

   Exactly two switches A–D are on. Claims: A off or B on(or both); C,D same state; exactly one of A,C on; B off. Exactly 3 claims are true. Which pair is on?

6. Answer

   C

   Question

   Exactly one of A,B holds. B requires C; C requires exactly one of D,E; D requires A; E excludes C. Which cannot hold?

Instructions

Study each picture and tap your choice.