MBE Logic

Imagine a question on the MBE in Civil Procedure about peremptory challenges. Jurors are stricken because of their age and the question looks towards whether such a challenge is valid.

Two answers follow:

(1) Yes, because peremptory challenges may be used to strike potential jurors for any reason.

(2) Yes because peremptory challenges may be used to strike potential jurors based on their age. 

You might well know from studying this area that (1) is not correct. There are some (though not many) constitutional limitations to peremptory challenges. But for the purpose of this post, assume that both answers look equally good. There may be a way to discern the correct answer by using a bit of logic.

Let's first assume that (1) is true and that peremptory challenges may be used to strike potential jurors for any reason. If peremptory challenges may be used to strike potential jurors for any reason, then (2) is correct as well. Because if peremptory challenges may be used to strike potential jurors for any reason, then they they may be used to strike potential jurors based on age: after all, age is a reason!

But you cannot have 2 correct answers on the MBE. Since (1) being correct would require (2) to be correct, (1) is therefore incorrect. 

The same does not follow in the reverse. Claiming that peremptory challenges may be used to strike potential jurors based on age does not require that one accept that these challenges can be used for any reason. In other words, claiming that (2) is correct does not require that (1) is also correct. 

Because claiming that (1) is correct requires that (2) is also correct, but claiming that (2) is correct does not require that (1) is correct, (2) is the correct answer. 

The above would all be quite a lot if it only applied to peremptory challenges. But far from it. This type of logic is another tool you can use when you've narrowed it down to 2 answers. So often students tell me "I can get it down to 2." This type of reasoning will help you to better get it down to 1.