- PowerScore Staff
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- Wed Jan 20, 2010 12:00 am
#45764
Complete Question Explanation
(The complete setup for this game can be found here: lsat/viewtopic.php?t=8976)
The correct answer choice is (B)
This is the defining question of the game. From the language in the question, it is clear that one of the five variables listed in the answer choices must always be advertised during the second week, yet prior to this question very few students realize that one of the products must always be advertised during week 2. Answering this question correctly is crucial since this information will definitely impact your ability to answer the subsequent questions both quickly and accurately.
The easiest way to attack this question is to again use the information from the hypothetical created in question #18. From answer choice (B) in that question, it is certain that either J or G must be the product advertised in week 2. Let us stop and take a moment to analyze this critical insight. First, as indicated by the question stem to #20, you now know that one of the products will always be advertised on week 2. If you did not discover this inference previously (and most people do not), you know you are missing a key piece of information that will undoubtedly help you solve not only question #20, but other questions as well.
When you know that one of the products must be advertised on week 2, then you can deduce that every single solution to the game will contain that product on week 2. This is a vital point since you can then look at any other hypothetical and immediately know that one of the two products listed on week 2 will be the one that is always on week 2. So, in question #18, when we determine that (B) is the correct answer, we know that either J or G must be the product that is always on week 2, and we can then look at only J or G in question #20. If there were other hypotheticals we could look at those also, and we would see that either J or G would always be present. For example, if another question produced J and K on week 2, this would show G does not have to be on week 2, and G would be eliminated from consideration; since J would be the only common variable between the two hypotheticals, then J would be proven correct. Thus, even though question #18 lists just one possible schedule of ads (“could be” a schedule of ads) it will still contain the product that we know from the wording of question #20 must always be on week 2.
Another way of thinking about questions #18 and #20 would be to say that if a product must always be advertised on week 2, and then if it does not appear on week 2 in one of the solutions, then how can that particular product be the one that is always on week 2? Therefore, any product not on week 2 in the solution to question #18 is immediately eliminated as the product that must always be advertised on week 2 (for example, if (D) was the answer to #20, then L would be in every solution to the game. But L is not in the solution to #18, so how could it be L?).
In applying this thinking to similar questions in other games, whenever you encounter a question that indicates that a variable must be in a certain group or position, then every other solution to the game will contain that variable in that position. So, if a question asks, “Which one of the following people must always be in the first group of runners?” and the correct answer to another question indicates that W, X, and Y are the only runners in the first group, then you would automatically know that one of W, X, and Y would have to be the runner that is always in the first group. Similarly, if a question asks, “Which one of the following must always be the third factory inspected?” and the correct answer to another question indicates that P is the third factory inspected, then you would automatically know that P is always the third factory inspected.
Returning to our consideration of G and J from question #18, the fact that one of those two must be the correct answer eliminates answer choices (C), (D), and (E) in question #20, once again demonstrating how important it is for you to answer List questions correctly and then use their information when applicable. Now that the contenders have been narrowed to two, you can easily make a hypothetical that proves or disproves one of the answers. Let us begin by attempting to prove that G does not have to be advertised in week 2 (it is almost always easier to disprove a Must Be True statement than prove it). The following hypothetical proves that answer choice (A) is incorrect:
Since answer choice (A) can be disproved, it follows that answer choice (B) is correct and J must be advertised during week 2. We can then infer that H must be advertised during week 1 (Why must H be advertised during week 1? Because in this question we discover that J must be advertised during week 2. Adding that piece of information to the first rule of the game then leads us to the inference that H must be advertised during week 1).
Adding these new inferences and Not Laws, we arrive at the following optimal setup for the game:
Note that H cannot be advertised in weeks 2 or 3 due to the second rule (that is, if H is the doubled variable it would have to be in 1-4). J cannot be doubled since that would also require H to be doubled—a violation of the rules. Therefore, J can be eliminated from weeks 1, 3, and 4. Since G must be advertised with either J or O, and J and O cannot be doubled, G must be advertised during week 2 or 3, and thus G cannot be advertised during weeks 1 or 4.
The above setup is optimal and should be used for all subsequent questions. Of course, you would want to check the previous questions to make sure you have not made any errors.
Perceptive students may have noticed another way to disprove answer choice (A) in this question. If G is advertised during week 2, then automatically J must also be advertised during week 2, since G must be advertised with either J or O, and O cannot be advertised during week 2. Since selecting answer choice (A) would automatically make answer choice (B) correct, answer choice (A) must be incorrect since there can be only one correct answer.
An additional note on the difficulty of this game: the importance of the inference contained in this question is reflected in the very nature of the questions themselves. Six of the seven questions in this game are Global, which means that most of the questions are based on information derived from the initial setup. If you miss this one key inference or never answer this question, you are automatically at a disadvantage in answering the rest of the questions. In other words, if you skip this question, you are passing on a chance to discover a major inference that applies to every other question.
(The complete setup for this game can be found here: lsat/viewtopic.php?t=8976)
The correct answer choice is (B)
This is the defining question of the game. From the language in the question, it is clear that one of the five variables listed in the answer choices must always be advertised during the second week, yet prior to this question very few students realize that one of the products must always be advertised during week 2. Answering this question correctly is crucial since this information will definitely impact your ability to answer the subsequent questions both quickly and accurately.
The easiest way to attack this question is to again use the information from the hypothetical created in question #18. From answer choice (B) in that question, it is certain that either J or G must be the product advertised in week 2. Let us stop and take a moment to analyze this critical insight. First, as indicated by the question stem to #20, you now know that one of the products will always be advertised on week 2. If you did not discover this inference previously (and most people do not), you know you are missing a key piece of information that will undoubtedly help you solve not only question #20, but other questions as well.
When you know that one of the products must be advertised on week 2, then you can deduce that every single solution to the game will contain that product on week 2. This is a vital point since you can then look at any other hypothetical and immediately know that one of the two products listed on week 2 will be the one that is always on week 2. So, in question #18, when we determine that (B) is the correct answer, we know that either J or G must be the product that is always on week 2, and we can then look at only J or G in question #20. If there were other hypotheticals we could look at those also, and we would see that either J or G would always be present. For example, if another question produced J and K on week 2, this would show G does not have to be on week 2, and G would be eliminated from consideration; since J would be the only common variable between the two hypotheticals, then J would be proven correct. Thus, even though question #18 lists just one possible schedule of ads (“could be” a schedule of ads) it will still contain the product that we know from the wording of question #20 must always be on week 2.
Another way of thinking about questions #18 and #20 would be to say that if a product must always be advertised on week 2, and then if it does not appear on week 2 in one of the solutions, then how can that particular product be the one that is always on week 2? Therefore, any product not on week 2 in the solution to question #18 is immediately eliminated as the product that must always be advertised on week 2 (for example, if (D) was the answer to #20, then L would be in every solution to the game. But L is not in the solution to #18, so how could it be L?).
In applying this thinking to similar questions in other games, whenever you encounter a question that indicates that a variable must be in a certain group or position, then every other solution to the game will contain that variable in that position. So, if a question asks, “Which one of the following people must always be in the first group of runners?” and the correct answer to another question indicates that W, X, and Y are the only runners in the first group, then you would automatically know that one of W, X, and Y would have to be the runner that is always in the first group. Similarly, if a question asks, “Which one of the following must always be the third factory inspected?” and the correct answer to another question indicates that P is the third factory inspected, then you would automatically know that P is always the third factory inspected.
Returning to our consideration of G and J from question #18, the fact that one of those two must be the correct answer eliminates answer choices (C), (D), and (E) in question #20, once again demonstrating how important it is for you to answer List questions correctly and then use their information when applicable. Now that the contenders have been narrowed to two, you can easily make a hypothetical that proves or disproves one of the answers. Let us begin by attempting to prove that G does not have to be advertised in week 2 (it is almost always easier to disprove a Must Be True statement than prove it). The following hypothetical proves that answer choice (A) is incorrect:
Since answer choice (A) can be disproved, it follows that answer choice (B) is correct and J must be advertised during week 2. We can then infer that H must be advertised during week 1 (Why must H be advertised during week 1? Because in this question we discover that J must be advertised during week 2. Adding that piece of information to the first rule of the game then leads us to the inference that H must be advertised during week 1).
Adding these new inferences and Not Laws, we arrive at the following optimal setup for the game:
Note that H cannot be advertised in weeks 2 or 3 due to the second rule (that is, if H is the doubled variable it would have to be in 1-4). J cannot be doubled since that would also require H to be doubled—a violation of the rules. Therefore, J can be eliminated from weeks 1, 3, and 4. Since G must be advertised with either J or O, and J and O cannot be doubled, G must be advertised during week 2 or 3, and thus G cannot be advertised during weeks 1 or 4.
The above setup is optimal and should be used for all subsequent questions. Of course, you would want to check the previous questions to make sure you have not made any errors.
Perceptive students may have noticed another way to disprove answer choice (A) in this question. If G is advertised during week 2, then automatically J must also be advertised during week 2, since G must be advertised with either J or O, and O cannot be advertised during week 2. Since selecting answer choice (A) would automatically make answer choice (B) correct, answer choice (A) must be incorrect since there can be only one correct answer.
An additional note on the difficulty of this game: the importance of the inference contained in this question is reflected in the very nature of the questions themselves. Six of the seven questions in this game are Global, which means that most of the questions are based on information derived from the initial setup. If you miss this one key inference or never answer this question, you are automatically at a disadvantage in answering the rest of the questions. In other words, if you skip this question, you are passing on a chance to discover a major inference that applies to every other question.
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Dave Killoran
PowerScore Test Preparation
Follow me on X/Twitter at http://twitter.com/DaveKilloran
My LSAT Articles: http://blog.powerscore.com/lsat/author/dave-killoran
PowerScore Podcast: http://www.powerscore.com/lsat/podcast/
PowerScore Test Preparation
Follow me on X/Twitter at http://twitter.com/DaveKilloran
My LSAT Articles: http://blog.powerscore.com/lsat/author/dave-killoran
PowerScore Podcast: http://www.powerscore.com/lsat/podcast/
