October 2005 Logic Games #2

[helplaw2008]

Pretty difficult, any one has an idea how to approach this?

[KaplanLSATInstructor]

If I'm not mistaken, this is the light switch game. Actually, it's not as complicated as it seems. It's a classic game of selection (just decide which switches are on), with one twist: the circuit load. If you understand the circuit load issue, the game isn't so bad.

Based on the opening, the circuit load is simply the number of switches that are on. This is important for the last rule. Basically, the last rule says that if the circuit load is some number X, then switch #X must be on. For example, if there are three switches on, one of those switches must be Switch 3. If four switches are on, then Switch 4 must be among them.

The other two rules are standard formal logic.

To illustrate how the circuit load applies in a question, look at question 8:

Q. 8 says that exactly two switches are on. That means (based on the last rule) one of them must be Switch 2. According to the second rule, if Switch 4 were on, then Switch 2 would have to be off. So, since Switch 2 is on, the contrapositive tells us that Switch 4 must be off... and that's your answer to the question.

Let me know you need further explanation.

- Chris

[LSAT All Star]

Sometimes people get hung up at the beginning of a game when they cannot get a diagram to start with.  These "in or out" games are the usual culprits.  For these games, the diagrams will be relatively simple but they will not develop until you get to the local restrictions.  You have to recognize these.  You cannot waste time at the beginning searching for a diagram that does not exist. 

When you go through the initial restrictions and you do not see any unconditional restrictions or any way to limit the possibilities to two (maybe three, max four) options, that is the clue that you need to head to the questions. 

This game provides a very good example.  (In fact, I use it in my games book).  Once you realize the initial restrictions are not going to give you a diagram, the whole game ends up being fairly simple.  The first question is just a normal first question.  You do it the normal way - go restriction by restriction and eliminate response options until only one is left.  That will give you a feel for how the game is going to play.  Then, each subsequent question has local restrictions (until you get to the last one).  Once you have the locals, you can start drawing things out and the game should go fairly smoothly and quickly.  (There just are not very many restrictions or variables you have to deal with). 

[EarlCat]

Other than the "load of the circuit" clue, this game works exactly like the birds-in-the-forest game.

[hopeful1985]

Other than the "load of the circuit" clue, this game works exactly like the birds-in-the-forest game.

+1 it's a pretty standard grouping game. even reminds me of one of the 1997 games with the seven friends or something (Umiko, Y, W, Z, T, S, R,) sick how I know that lol.

[EarlCat]

Other than the "load of the circuit" clue, this game works exactly like the birds-in-the-forest game.

+1 it's a pretty standard grouping game. even reminds me of one of the 1997 games with the seven friends or something (Umiko, Y, W, Z, T, S, R,) sick how I know that lol.

Yeah, the photograph game..  same thing again.

[KaplanLSATInstructor]

Other than the "load of the circuit" clue, this game works exactly like the birds-in-the-forest game.

+1 it's a pretty standard grouping game. even reminds me of one of the 1997 games with the seven friends or something (Umiko, Y, W, Z, T, S, R,) sick how I know that lol.

Yeah, the photograph game..  same thing again.

And don't forget the fruit stand game with the figs, kiwi, watermelon, tangerines, etc. One of my all-time favorites.

[hopeful1985]

Other than the "load of the circuit" clue, this game works exactly like the birds-in-the-forest game.

+1 it's a pretty standard grouping game. even reminds me of one of the 1997 games with the seven friends or something (Umiko, Y, W, Z, T, S, R,) sick how I know that lol.

Yeah, the photograph game..  same thing again.

And don't forget the fruit stand game with the figs, kiwi, watermelon, tangerines, etc. One of my all-time favorites.

heck yeah i love that game!