To those who thought c was also necessarily true, please realize that you can’t reverse the logical relationship. You MUST get straight what necessary and sufficient conditions mean or you won’t do well on the LSAT. If A then B (A—–> B) does NOT also show that “If B then A”. Example: If you study hard (A), then you will do well on the LSAT (B). However, just because you do well on the LSAT doesn’t mean you necessarily studied hard. You could have just had good luck!
Incidentally, yours is a very common mistake when dealing with Formal Logic; you have arrived at the logical converse of the given chain. Simply reversing the logic does not provide us with an adequate logical equivalent.
Actually the rules as stated do not make C necessary. We can deduce nothing for certain if Mike is invited to the party. Mike’s invitation to the party only results as the necessary consequence of not inviting Willy (the sufficient condition). In other words, inviting Mike is not enough information to produce a necessary result.
You said B) if Willy is invited then Andrew must not be invited. However, your C is true too…If Mike is invited Todd must not be!!! Did you write this wrong?? You have two true answers.
glad I found this
To those who thought c was also necessarily true, please realize that you can’t reverse the logical relationship. You MUST get straight what necessary and sufficient conditions mean or you won’t do well on the LSAT. If A then B (A—–> B) does NOT also show that “If B then A”. Example: If you study hard (A), then you will do well on the LSAT (B). However, just because you do well on the LSAT doesn’t mean you necessarily studied hard. You could have just had good luck!
Tight Work!
Incidentally, yours is a very common mistake when dealing with Formal Logic; you have arrived at the logical converse of the given chain. Simply reversing the logic does not provide us with an adequate logical equivalent.
Actually the rules as stated do not make C necessary. We can deduce nothing for certain if Mike is invited to the party. Mike’s invitation to the party only results as the necessary consequence of not inviting Willy (the sufficient condition). In other words, inviting Mike is not enough information to produce a necessary result.
You have two correct answers for Mike invited one…B is true as well as C.
You said B) if Willy is invited then Andrew must not be invited. However, your C is true too…If Mike is invited Todd must not be!!! Did you write this wrong?? You have two true answers.