PT 58, September 2009, Logic Games #3 and #5

[Tailgator2010]

These two questions strike me as unusual, but I've run across more of these on the recent tests. Does anyone have any general tips on how to solve questions like this?

Thanks in advance.

[lawdog]

Hey Tailgator,

Those are interesting, and a little different--it must be tough for the test makers to keep coming up with new twists on logic games questions.

In general, most questions in logic games either require you to determine an outcome based on the global setup of the game, or give you a new constraint and require you to note its ramifications. The questions that you reference both provide a given outcome, and you are required to figure out what will dictate that outcome. Basically, they require that a particular conclusion be justified by one of the answer choices. In question #3, for example, the correct answer choice will dictate the placement of every remaining variable.

It's a good idea in general to notice which variables are constrained by rules and which aren't. In this case, the only "wildcard" variable--the one which has no rules directly governing its placement--is variable S, and the first answer choice I would try with a question like this one would be the choice that somehow deals with S (all of the other variable are subject to constraints, so maybe adding a rule to constrain the wildcard will dictate the whole setup). 

If we try out answer choice (E) (the only choice which deals with variable S) we can see that this is the correct answer:
If S was constructed in 604, then 605 is the only remaining year during which H could have been constructed. Since we also know that G>L>F, those variables must have been build in years 601, 602, and 603, respectively. M must take the only space which remains, so it must have been constructed in year 601 (along with G).


For question #5, the question requires you to find the choice which dictates L's construction in year 602. The same tip applies regarding use of the wildcard variable, so I would again start with the answer that deals with wildcard S. Again, if we try out answer choice (E), we can confirm it to be the right answer:

If S was started in 603, that leaves 604 and 605 to the right of S. H was begun during one of those two years, so one open space remains to the right of S (in either 604 or 605) which cannot be occupied by M (the global rules say that M < 604). So, F, like H, must have been constructed in either 604 or 605.
This leaves only 601 and 602. Since G had to have begun construction before L, G must have started in 601 (along with M during that same year) and L must have started in 602. This confirms (E) to be the correct answer choice.

[Tailgator2010]

In general, most questions in logic games either require you to determine an outcome based on the global setup of the game, or give you a new constraint and require you to note its ramifications. The questions that you reference both provide a given outcome, and you are required to figure out what will dictate that outcome. Basically, they require that a particular conclusion be justified by one of the answer choices. In question #3, for example, the correct answer choice will dictate the placement of every remaining variable.

It's a good idea in general to notice which variables are constrained by rules and which aren't. In this case, the only "wildcard" variable--the one which has no rules directly governing its placement--is variable S, and the first answer choice I would try with a question like this one would be the choice that somehow deals with S (all of the other variable are subject to constraints, so maybe adding a rule to constrain the wildcard will dictate the whole setup). 

Awesome, the above makes total sense to me. I never thought of it that way before, and I will add that to my bag of strategies. Thanks for the help!!!