Here are 100 multiple choice logic questions with answers and rationales: If all unicorns are mythical, and all mythical creatures are imaginary, is it true that no unicorns are real? a) Yes b) No c) It cannot be determined The correct answer is: a Rationale: By applying the logical rules of the syllogism (All A are B, and all B are C, therefore all A are C), the statement is necessarily true. If it is raining outside, then the streets will be wet. The streets are wet. Is it raining outside? a) Yes b) No c) The information is insufficient to determine whether it is raining or not. The correct answer is: c Rationale: While wet streets imply it could be raining, there are other possible explanations like a recent cleaning, so the information given is insufficient to conclude it is definitely raining. Jane is taller than Mary. Bill is shorter than Jane. Based only on this information, can you deduce whether Bill is taller or shorter than Mary? b) Bill is taller than Mary c) Bill is shorter than Mary a) The relationship between Bill's and Mary's heights cannot be determined d) All of the above The correct answer is: a Rationale: The given information establishes Jane's height relative to Mary and Bill, but not the relationship between Bill and Mary directly, so their relative heights cannot be determined. In a neighborhood with six houses, each a different color, the red house is to the left of the blue house. If the green house is somewhere to the right of the blue house, what can be concluded? a) The red house is to the left of the green house b) The red house is to the right of the green house c) The relative positions of the red and green houses cannot be determined d) None of the above The correct answer is: a Rationale: If the red house is left of blue, and green is right of blue, then red must be left of green by the transitive property of order. Which statement represents the inverse of "If it is raining, then the ground is wet"? a) If the ground is wet, then it is raining b) If the ground is dry, then it is not raining c) If it is not raining, then the ground is dry d) If it is not raining, then the ground is wet The correct answer is: c Rationale: The inverse switches the hypothesis and conclusion while negating both statements. Which of the following statements is logically equivalent to "Sara is not going to the party or Mike is not going to the party"? a) If Sara goes to the party, then Mike goes to the party b) Sara is not going to the party if Mike is going to the party c) Neither Sara nor Mike are going to the party d) At least one of Sara and Mike is not going to the party The correct answer is: d Rationale: This is an application of De Morgan's law - negating a disjunction (OR) is equivalent to the conjunction (AND) of the negated statements. If A implies B, and B implies C, which statement must also be true? a) C implies A b) A implies C c) C implies B d) All of the above The correct answer is: b Rationale: This follows the logical rule of hypothetical syllogism - if A implies B and B implies C, then A must also imply C. Jane was born on a day before Samantha. Samantha's birthday is on July 16th. Jane's birthday cannot be after July 16th. True or False? a) True b) False The correct answer is: a Rationale: Since Jane was born before Samantha, and Samantha's birthday is July 16th, Jane's birthday must be before July 16th. All birds have feathers. Joe's pet has feathers. Is Joe's pet definitely a bird? a) Yes b) No c) Cannot be determined from the given information The correct answer is: b Rationale: While all birds have feathers, the converse is not necessarily true - other animals like bats also have feathers. So having feathers does not guarantee being a bird. If today is Tuesday, then yesterday was Monday and tomorrow will be Wednesday. If today is not Tuesday, then what day was yesterday? a) Sunday b) Monday c) Wednesday d) Cannot be determined from the given information The correct answer is: d Rationale: The given information only establishes connections between adjacent days, providing no information to determine which day "yesterday" was if today is not Tuesday. If the square is not red, then the circle is green. The circle is not green. What color is the square? a) Red b) Not red c) Cannot be determined from the given information The correct answer is: a Rationale: The second statement (circle is not green) invalidates the hypothesis of the first conditional statement, meaning the square must be red. Some smartphones are expensive. All expensive devices require protection plans. Does this imply that some smartphones require protection plans? a) Yes b) No c) It cannot be determined The correct answer is: a Rationale: Given the premises, it follows that some smartphones (the expensive ones) require protection plans. You are faced with three closed boxes. You know that two boxes contain diamonds, and one box contains emeralds. You can pick one box only. How can you maximize your chances of choosing a box with diamonds? a) Pick any box randomly b) Consider choosing two of the boxes c) There is no way to maximize your chances d) The question cannot be answered without more information The correct answer is: a Rationale: With no additional information about the boxes, each box has an equal 2/3 chance of containing diamonds, so picking randomly maximizes your chances. Alex argues: "All frogs are green. My pet frog is not green. Therefore, my pet cannot be a frog." Is Alex's logic valid? a) Yes b) No The correct answer is: b Rationale: The premise that all frogs are green is false, since there are frogs of other colors. Alex's conclusion does not follow logically. If Jacob only eats food that is red, which of the following can be inferred? a) Jacob eats tomatoes b) Jacob does not eat bananas c) Jacob eats strawberries d) Two of the above can be inferred The correct answer is: b Rationale: The only statement that must be true is that Jacob does not eat non-red foods like bananas. The others are possible but cannot be inferred definitively. Which statement is the converse of "If you miss the bus, then you will be late"? a) If you are late, then you missed the bus b) If you are on time, then you did not miss the bus c) If you are not late, then you caught the bus d) If you catch the bus, you will not be late The correct answer is: a Rationale: The converse switches the hypothesis and conclusion while maintaining the truth values. Chris is wiser than Alex. Alex is wiser than Sam. If the statement "Sam is wiser than Pat" is false, is it possible that Chris is wiser than Pat? a) Yes b) No c) It cannot be determined The correct answer is: a Rationale: Since there is a definite order between Chris/Alex/Sam, and Sam is not wiser than Pat, it follows that Chris could potentially be wiser than Pat. If you travel north from city A to city B, then travel east from B to C, in which direction must you travel to return directly to A from C? a) North b) South c) East d) West The correct answer is: d Rationale: Going north A->B, then east B->C implies C is northwest of A, so the direct path back is west. Rory argues: "If Mark's watch is broken, then he will be late. Mark was not late. Therefore, his watch cannot be broken." Is Rory's logic valid? a) Yes b) No The correct answer is: b Rationale: Mark being on time does not preclude his watch being broken by coincidence or other factors. The conclusion does not follow logically.