1) If they are a boy, then their name is not on the ID A statement’s contrapositive is logically equivalent to the statement itself. A contrapositive is found by negating the subject and predicate of a conditional sentence and then having them change places. In this example, answer choice 3 is a contrapositive which means it is logically equivalent to the original statement 2) B and D If E were a boy, then A would be a boy, as would C, B, and D by default of the following statements. That amounts to all 5 people being boys. If A were a boy, then C, B, and D would as well. That amounts to 4. If C were a boy, then B and D would also be boys. That amounts to 3. But if B were a boy, then D would also be a boy, and hence since it amounts to only 2, this is correct. 3) C If E and C were not behind A, they were in line with A. Thus, A, C, and E must be in seats 1, 2, and 3 respectively. If C was not to the left of A, C was on the right of A since there are only 3 seats. Seat 3 is on the right of seat 2, thus C must be in seat 3. 4) 2 and A The only type of card that would prove this statement wrong is one in which there is a vowel on one side and an even number on the opposite side. Therefore, the two cards you would want to flip over are the two cards with the possibility of having this arrangement, 2 and A. You would want to flip over A since if it had an even number on the other side this would prove the rule wrong. You would also want to flip over 2 since if it had a vowel on the other side this would prove the rule wrong. There is no point in flipping over C, 3, and 5 as no matter what is on the other side, it is impossible for the rule to be shown to be false.