Q13 - Which one of the following exhibits a pattern of reaso

[Jesslxh]

Hi everyone, I have been baffled by this question for over an hour now. My discussion with my fellow study mates has derived many explanations. We all agree the answer is A. But we see differently why answer choice D could be wrong. Here it is..


In the stimulus, if that insect is a bee, it can only sting once. It only did sting once. So it is a bee
B---> SO
SO ----> B

(B= bee, SO= sting once)


We have no problem with this part.

For answer choice A:

S ----> ~SS
~SS ----> S

(S = spring, SS stop sneezing)

Again, no problem with this part too.


However, in answer choice D,

The first part of the answer says : Only one more thunderstorm was needed to ruin that roof.
Which one is the sufficient condition? Is it thunderstorm? or ruin that roof?

Most of my study mates agreed that

OMT ----> RR

(OMT = one more thunderstorm, RR= ruined roof)

Even though "only" is the indicator of a necessary condition, they think in this case it introduces a sufficient condition. Why??? I don't understand!

Can I please have an instructor to help me out? Thank you!

[ManhattanPrepLSAT1]

Great question Jesslxh!

The issue is that there are two necessary terms: "only" and "needed." Occasionally (lets say fewer than 15 times in total), the LSAT will phrase the conditional with "only one more ... is needed" or "... depends only on one thing." In these cases, treat them as sufficient.

Hope that helps!

[a8l367]

For answer choice A:

S ----> ~SS
~SS ----> S

(S = spring, SS stop sneezing)

Is it?
Maybe:

S ----> ~SS
JSO ----> S (???)

(S = spring, SS stop sneezing, JSO = just sneezed once)

So we should assume that -SS = JSO. But does it?

Could someone clairfy?

[LucyS239]

I have the same question above, can someone explain for us?

[JosephV]

For answer choice A:

S ----> ~SS
~SS ----> S

(S = spring, SS stop sneezing)

Is it?
Maybe:

S ----> ~SS
JSO ----> S (???)

(S = spring, SS stop sneezing, JSO = just sneezed once)

So we should assume that -SS = JSO. But does it?

Could someone clairfy?

First, please note that answer choice (A) does not say "I just sneezed once." It says "I just sneezed."

Second, yes, you should assume that ~SS = JS (cannot stop sneezing = just sneezed). Why?

The stimulus could be re-written as: "When (remember, when is equivalent to "if") it is spring, I sneeze. I've just sneezed. Therefore it is spring." Diagrammed (using the ManhattanPrep way) as:

spring ---> sneeze
sneeze
spring

Answer choice (A) fits the same pattern of faulty logic.