Author: Scott

Before I decided I needed time tactics, I often spent two minutes on a logic game question that I should have gotten right in ten or fifteen seconds. The question would be something simple: “Which of the following must be true?” Time after time, I would slog my way through answer choice A, B, C, and D, proving that each one might be false. Then I would reach answer choice E and realize that it must be true–I already had it penciled in on my diagram. The geniuses who write the LSAT know all about people like me, and they routinely set us up for failure. But once you study time tactics, you can beat them at their own game.

A question like “which of the following must be true” is a global “must be true” question. In subsequent chapters, we will talk about “local” questions (where the question begins with an “if” that established a new condition for just that one question) and “must be false” questions. As we explore the different variations of “must be” questions, we will discover the optimal path through all such problems. For now, our “must be method” is very simple:

Must Be Method:
1) Could be easy!

Let’s try this out on the following simple sequencing game. Here are the scenario and rules:

Six law students–Allison, Briyant, Clarence, Daniel, Elisheva, and Faith–decide to chase Pokémon instead of studying. Each student catches exactly one Pokémon at a time. The order in which they catch them is determined by the following rules:

Elisheva catches hers before Daniel,
Allison gets hers first or last.
Neither Elisheva nor Faith catches the first one.
Clarence catches his before Allison or Briyant but not both.

Here is my sketch for this game. The blue items on the diagram are spelled out in the initial rules; the orange items are deductions I have made.

Note: several of our time tactics depend on being able to quickly and accurately check through all the rules, so I list all of the rules in order. If a rule can be completely expressed directly on the diagram, I note that to the left of the rule number; otherwise I write in the rule to the right of the rule number.

Turn on your stopwatch app and see how long it takes you to answer the following question.

Which of the following must be true?

A) At least two students catch a Pokémon before Allison.
B) At least two students catch a Pokémon before Briyant.
C) At least two students catch a Pokémon before Clarence.
D) At least two students catch a Pokémon before Daniel.
E) At least two students catch a Pokémon before Elisheva.

How long did that take? Think about the way you went about answering the question.

Now let’s apply our “could be easy” tactic to this same question. Every single answer mentions “at least two students,” which ought to focus our attention somewhere on the diagram. If at least two students must go before somebody, that somebody can’t go first or second. A quick look at the diagram shows that Daniel is the only student who can’t go second–and he can’t go first, either. Answer choice D is about Daniel–and we’re done!

Your elapsed time for this question, which includes reading the question, looking at the answers, checking the second spot on the diagram, and finding answer choice D should be about fifteen to twenty seconds.

Note–this kind of speed depends on having deduced that Daniel couldn’t catch the second Pokémon when you first set up the game. If you don’t routinely see such deductions when you first go through the rules, you need more work on logic game basics. Don’t worry about that now, however–throughout this book, you’ll have my diagrams in front of you as you tackle each question.

Let’s sum up what we’ve learned about the “could be easy” rule. A “must be true” question could be so easy that you can just look at your diagram and find the answer in a matter of seconds. This is especially likely to be true if you made some good deductions on your setup. When you see a global “must be true” question, quickly skim through all five answers to find out whether you have already figured out the answer. If you have, grab that answer and go–you don’t need to look any further!

The first question in most logic games is very predictable–it asks which of the following five answers are acceptable outcomes.  The Law School Admission Council refers to these as “orientation questions,” since they are intended to orient you to the setup conditions. In The Official LSAT Superprep II, the LSAC tells you exactly how to answer such questions:

For such questions, probably the most efficient approach is to take each condition in turn and check to see whether any of the answer choices violates it. As soon as you find an answer choice that violates a condition, you should eliminate that answer choice from future consideration–perhaps by crossing it out in your test booklet. When you have run through all of the setup conditions in this fashion, one answer choice will be left that you haven’t crossed out: that is the correct answer.

This paragraph is the gold standard for “how to solve a logic game problem.” It is short, accurate, and authoritative. It not only tells you how to get the problem right every single time, it tells you how to get it right as efficiently as possible. What The Official LSAT Superprep II doesn’t do is explain why this is the fastest and best way to answer such questions, nor does it explain why other methods are slower and less reliable.

There are three ways to solve an orientation question. The first (which is far too common) is to have no strategy. The second is to tackle the question rule by rule, as the LSAC suggests. The third is to start with answer choice A, go through the rules one by one, eliminate it if it breaks a rule, and move on to answer choice B. This “answer by answer” approach will usually produce the right answer–but it is significantly slower and less reliable than the “rule by rule” approach. Let me explain why.

The “rule by rule” approach is optimal because it minimizes time-consuming steps and eliminates the possibility of “false positives.” By “false positive,” I mean an answer that appears to obey all the rules but really doesn’t. The people who write logic games know how most people try to solve them, and they can and will use that against you. Thus, if answer choice C appears to follow every rule, it can still be wrong–some other rule may be buried in the initial paragraph that spells out the scenario. You can’t really be sure that C is right until you know that every other answer is wrong,

Here are the steps for a “rule by rule” solution:

1. Look at the rule.
2. Figure out what you’re looking for in a wrong answer (i.e., “if A comes before B, that breaks this rule”).
3. Skim through each answer choice, looking for that pattern.
4. Cross off any answer(s) that break the rule.
5. Go back to step 1 and repeat until only one answer is left.

Compare that to the “answer by answer” approach:

1. Look at the answer.
2. Go up to the first rule.
3. Figure out what you’re looking for in a wrong answer (i.e., “if A comes before B, that breaks this rule”).
4. Go back to your answer, looking for that pattern.
5. Cross off the answer if it breaks the rule and jump ahead to  step 18.
6. Otherwise, go up to the second rule.
7. Figure out what you’re looking for in a wrong answer (i.e., “if A comes before B, that breaks this rule”).
8. Go back to your answer, looking for that pattern.
9. Cross off the answer if it breaks the rule and jump ahead to step 18.
10. Otherwise, go up to the third rule.
11. Figure out what you’re looking for in a wrong answer (i.e., “if A comes before B, that breaks this rule”).
12. Go back to your answer, looking for that pattern.
13. Cross off the answer if it breaks the rule and jump ahead to step 18.
14. Otherwise, go up to the fourth rule.
15. Figure out what you’re looking for in a wrong answer (i.e., “if A comes before B, that breaks this rule”).
16. Go back to your answer, looking for that pattern.
17. Cross off the answer if it breaks the rule.obeys
18. This is the step where you get in trouble. Is this the final answer choice? Is it the only one that isn’t crossed off? If you haven’t reached answer choice E yet, you could be making a big mistake right here. So if you aren’t at E yet, move on to the next answer and go back to step 1.

That’s the theory. Let’s put it into practice. Here’s a simple orientation question for a logic game:

Allison, Bradley, Clarence, Daniel, Elisheva, and Faith are so tired of prepping for the LSAT that they have all decided to play Pokémon Go. Between them, they manage to catch and hatch Pheremosa, Quagsire, Relisprout, Solgaleo, Togetic, and Uxie. Each Pokémon is caught one at a time, but not every law student necessarily catches a Pokémon. The order in which the students catch the Pokémon obeys the following rules:

Bradley refuses to catch a Pokémon until Allison gets one.
None of the girls try to catch more than one Pokémon.
Uxie is caught first or last.
Pheremosa is  caught after Relisprout.

Question 1: Which of the following is an acceptable list of the order of students and the Pokémon they catch?

A) Daniel catches Uxie, Allison catches Relisprout, Bradley catches Pheremosa, Faith catches Quagsire, Bradley catches Sogaleo, Clarence catches Togatic.

B) Allison catches Relisprout, Bradley catches Uxie, Daniel catches Pheremosa, Faith catches Quagsire, Elisheva catches Sogaleo, Bradley catches Togatic.

C) Clarence catches Uxie, Daniel catches Sogaleo, Faith catches Relisprout, Allison catches Pheremosa, Bradley catches Quagsire, Faith catches Togatic.

D) Allison catches Relisprout, Faith catches Quagsire, Bradley catches Pheremosa, Daniel catches Sogaleo, Bradley catches Togatic, Daniel catches Uxie.

E) Bradley catches Uxie, Allison catches Relisprout, Clarence catches Pheremosa, Faith catches Togetic, Elisheva catches Quagsire, Daniel catches Sogaleo.

I solved this problem “answer by answer.” It took me 1:16, and I sort of cheated because I stopped when I got the answer that obeyed all the rules. (If this had been a tricky question with a rule buried in the scenario, I would have gotten it wrong.) I did the same problem “rule by rule” and it took my 0:36. That’s just under half as long and the answer was more trustworthy–I eliminated four wrong answers and the only answer left had to be right.

Try this yourself. If you don’t see a dramatic difference between the “answer by answer” and the “rule by rule” approach, leave a comment below. If you do find that the “rule by rule” approach is significantly faster (and more reliable), make sure you use it from now on. You’re on your way to learning time tactics!