Q14

[kjg56]

Can someone walk me through why E is correct and how you would go about answering this question. Did you try to disprove each answer choice or did you make an initial inference that directed you to the correct answer?

Thank you!

[fmuirhea]

For local/specific questions (those that typically begin with "if") that ask you what "must be true," the credited response is something you should be able to deduce based on the new information. Sometimes, these deductions aren't immediately obvious, and you have to switch to testing answer choices to disprove and thus eliminate them, but, in this case, (E) is a deduction you can make from combining the new information with the rules. In fact, the new information in this question allows you to completely determine the assignment of testers to bikes.

I set up my diagram with the bikes and days as the rows and columns and assigned testers to bikes. The final rule gives you a Y S block that you can deduce must be assigned to either F or G (it cannot be assigned to H because T must test H on one of the days, and it cannot be assigned to J because Y cannot test J). I think this is the most important initial deduction, and Patrick outlines the resulting frames in the diagram thread: https://www.manhattanprep.com/lsat/foru ... t5432.html

For this question, since T is testing G on the second day, T must test H on the first day (T must test H according to the rules), and the Y S block must therefore be at F (it can no longer be at G because T is in the way). This forces Y to test H on the second day (Y cannot test J according to the rules), which forces R to test J on the second day (it's the only slot left), which forces R to test G on the first day (no testers can test the same bike on both days), which forces S to test J on the first day (it's the only slot left):

___1_2
F | Y S
G| R T
H| T Y
J | S R

Since the new information in this question completely determined the diagram, you shouldn't have had to test any answer choices. I wonder if you either missed one of the initial rules or didn't make sure you'd made all of the deductions based on the new information before heading to the answer choices. The rule that testers cannot test the same bike twice was in the setup instead of being in the indented list of rules--did you spot and symbolize it?

With local/specific questions, add the new information to your diagram and mechanically go through your rules one at a time to see what else you can deduce--repeat this process any time you deduce something new. You should be able to make one clean run through the rules without making any more deductions before you head to the answer choices. If you make sure you've exhausted the deductions before looking at the answer choices, you'll probably have done enough work to get to the credited response. Defer brute force testing of answer choices until it's absolutely necessary!

[tommywallach]

Great response, Fm!

-t