Principle: A police officer is eligible for a Mayor's Commendation if the officer has an exemplary record, but not o...

Naz on April 1, 2015

Let's diagram this:

"A police officer is eligible for a Mayor's Commendation if the officer has an exemplary record, but not otherwise;"

NOTE: "if, but not otherwise" acts similarly to "if, but only if," which we know is a bi-conditional statement.

P1: ER ==> EMC
not EMC ==> not RE

EMC ==> ER
not ER ==> not EMC

"an officer eligible for the award who did something this year that exceeded what could be reasonably expected of a police officer should receive the award if the act saved someone's life."

NOTE: This is a tricky sentence. What are the sufficient conditions? We are saying if an officer is eligible for the award and they did something this year that exceeded what could be reasonably expected of a police officer and that specific act saved someone's life, then they should receive the award.

P2: EMC & DSE & SSL ==> SRA
not SRA ==> not EMC or not DSE or not SSL

Conclusion: "Officer Franklin should receive a Mayor's Commendation but Officer Penn should not."

C: Franklin : SRA & Penn : not SRA

Answer choice (B) is very tempting. It tells us that both Franklin and Penn have "ER," which, according to "P1," means that they both have "EMC." It tells us that they each saved a child's life earlier this year, but in doing so, Franklin was the only one that went beyond what could be reasonably expected of a police officer. So, that means that Franklin satisfies "DSE" and "SSL," but even though Penn saved a life, he did not do so while exceeding what could reasonably be expected of a police officer.

So, from answer choice (B), we know for Franklin, we have: EMC & DSE & SSl, which means we can conclude that Franklin should receive the award.

Now, from answer choice (B), we know that Penn has EMC. We do not know whether Penn did some other act this year that exceeded what could be reasonably expected of a police officer that also resulted in saving a life. Thus, we cannot say that Penn does or does not have "DSE" or "SSL."

Further, remember that the necessary conditions of a principle rule and its contrapositive create a viable option. Meaning, we could have "SRA" while not having "EMC" or "DSE" or "SSL." The principle never told us that these three conditions were the only way to see if someone should receive the award.

Thus, answer choice (B) cannot help properly draw out the conclusion.

Hope that clears things up! Please let us know if you have any other questions.

Meredith on November 8, 2019

So how does A specifically meet the requirements of applying this principle? In the explanation above it comes across B was not restrictive enough to eliminate other possibilities but how is A sufficient enough?