Q23

[AnnaT620]

Hello MPrep Team

Please could you also post an explanation of this answer?

Thank you!

[Misti Duvall]

Sure! According to the condition given, W presents on J and S, but not M. So we start with this:

G: __
R: __
W: J S

If W presents on S, then R does not (contrapositive of the second rule). And if no S, no M (contrapositive of the third rule), so R must present on J cause it's the only option left. Meaning the only place left for M is with G, and according to the third rule, M --> S. So the full diagram is:

G: M S
R: J (- S, - M)
W: J S (- M)

Answer choice (B) is correct. And this is ok for a could be true, since G could also present on J, but doesn't have to.

One tricky thing with this game is making sure to note the contrapositives (which you should do for any conditional rule). And keep track of the antis as well.

Hope this helps.