Which one of the following, if substituted for the constraint that the two restaurants must be separated by at least ...

shunhe on March 24, 2020

Hi @dannyod,

Thanks for the question! With respect to getting a video for this question, please contact our support staff by tapping “support” from the left menu or by calling 855.483.7862 ext. 2 Monday-Friday 9am-6pm PT. I am happy to provide an explanation in the meantime. We’re looking for a rule to substitute for the second rule dictating that the two Rs must be separated by at least two other businesses and that would have the same effects on the game. We know that because of the first rule, one of the Rs is always on one of the ends. To keep the effect of the second rule, we need something that keeps R on the other end by P (or at best in the middle), which would keep it at least two spaces away from the first R. (D) should immediately make us suspicious, because it concerns P, and P is always on the opposite end from one of the Rs. Taking a closer look at (D), it tells us that P and the nearest R are never more than two businesses apart. If that’s true, then one of the Rs always has to be within three spaces of P, which means it has to be at least two spaces away from the other R. This has the same effect as the second rule, and so (D) is the correct answer choice.

In general, with substitution questions, it’s good to look for answer choices that concern relevant variables in the way we did above. We noticed that P had a certain relation to R that we could exploit, and so looked for a rule that had P in it (as well as R). It also helps to keep track of your previous diagrams to help eliminate obviously wrong answer choices. Also, even if a rule allows/disallows one extra case, that rule is wrong and should be eliminated. Old rules will also often be connected to new rules—in this case, the old rule had to do with the distance between the two restaurants; the new rule had to do with the distance between the restaurant and the pharmacy. It’s not as common that the new rule will be something completely different from the old rule. And of course, don’t panic! Rule substitution questions in general are hard and time consuming.

Hope this helps! Feel free to ask any other questions that you might have.

dannyod on March 24, 2020

Thanks that is helpful! Can you please just clarify why/how A could be eliminated, since A is in fact also true under every scenario?

shunhe on March 25, 2020

Hi @dannyod,

Actually, (A) isn’t true under every scenario. Remember that for the rule substitution here, the new rule has to have the exact same effects as the old rule.

Let’s say that you put R in slot one and P in slot 7. We can fill out the rest of the board in the following manner:

R T R S O V P

And we see that this fulfills the other rules: T isn’t adjacent to V, and P is next to V. We also see that it fulfills the new rule: there is a restaurant in space 3. But it violates the old rule that the restaurants must be separated by at least two other businesses, and therefore, (A) isn’t an exact substitution.

We can also mirror this board, which would still be a legitimate board and have Rs in slots 5 and 7, which would still be inconsistent with the old rule while being consistent with the new one. Hope this helps!

dannyod on April 6, 2020

Sorry, but your answer is blank. Could you please re-post?

shunhe on April 7, 2020

Hopefully it works again, you might need to update the app?

Hi @dannyod,

Actually, (A) isn’t true under every scenario. Remember that for the rule substitution here, the new rule has to have the exact same effects as the old rule.

Let’s say that you put R in slot one and P in slot 7. We can fill out the rest of the board in the following manner:

R T R S O V P

And we see that this fulfills the other rules: T isn’t adjacent to V, and P is next to V. We also see that it fulfills the new rule: there is a restaurant in space 3. But it violates the old rule that the restaurants must be separated by at least two other businesses, and therefore, (A) isn’t an exact substitution.

We can also mirror this board, which would still be a legitimate board and have Rs in slots 5 and 7, which would still be inconsistent with the old rule while being consistent with the new one. Hope this helps!

dannyod on April 8, 2020

Thank you! An app update solved the problem and your explanation makes sense. Apologies for blowing up the message boards when I couldn't see.