I know I’m totally late with this, but I ran into the same problem… but for me it was the Logic Games Bible’s assertion that

if not J, than S

becomes in the contrapositive

if not S, than J

Which doesn’t make any sense to me. Am I missing something here?

to me, it should become

If S, than not J.

(BTW, I’m using an older version of the book, from approximately 2003)

I hate logic games–

but I hope you rocked your exam!
J

you are overcomplicating the last rule - it doesn’t say that jays and shrikes cannot coexist - it merely says that if one is not there, then the other will be. ie, at all times there are either jays or shrikes - or both, which is implied - but never the complete absence of jays AND shrikes. get it?

i love me some logic games too

I’ll bet if somebody told you you had to master devanagari by June, you’d start studying for the LSAT.

P.S. Learning devanagari at home in the States is hard. Learning it on the street in India is easy. You only have to see the English names of tailor shops and sweet emporiums rendered in devanagari a few times before it all clicks into place.

Talula,

The problem appears to be correct to me. I think you’re getting
confused when you say:

“We are left with only shrikes and jays, and we can only have one or
the other, not both, and not neither” and “I thought that the final
rule stated that either S or J, but not both, could be in the forest.”

The final rule–which I assume is the one that says “if jays are not in
the forest, then shrikes are”–does say that either jays or shrikes are
in the forest, but it doesn’t say that both are not. All the rule says
is that IF jays are not there, then shrikes will be. It doesn’t say
what happens if jays ARE there; for all we know from the rule, shrikes
might be there, too.

What you say about contrapositives is right, but not really to the
point. I suspect that you’re reading the rule to say “if and only if”,
which would make it true that not both jays and shrikes are in the
forest. Confusing “if” and “if and only if” is a common mistake.

Hope that helps.

if not j then s
if not s then j

however, since we do not have ‘if j then not s’ or ‘if s then not j’ statements it is possible to have both s and j. I thought about it in a more wordy situation:

If Jays clear out of the forest, then Shrikes will move in to replace them. If the Shrikes later move out, then the Jays will come back. However, if the Jays, say, get real hungry, they COULD come back early and fight with the Shrikes for the food.

I could be way off, but it seems clear to me.