PT 40 - Sec 3 #17

seaghost527
Posts: 22
Joined: Tue May 18, 2010 8:56 pm

PT 40 - Sec 3 #17

Postby seaghost527 » Sun Aug 15, 2010 9:54 pm

Can someone explain why the answer is (A).

I think the flawed reasoning is... If A > B, then B > A, which seemed to me to be present in (A), (D), and (E).

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yzero1
Posts: 185
Joined: Thu May 27, 2010 4:33 pm

Re: PT 40 - Sec 3 #17

Postby yzero1 » Sun Aug 15, 2010 10:13 pm

The relationship in the stimulus is a mistaken reversal of the two negated terms:
- Asked to do more than easy -> - Do all they can
- Do all they can -> - asked to do more than easy
(or in other terms, -A -> -B so -B -> -A)

You can also frame this as A->B so B->A. Whether the terms are negated doesn't matter. What matters is the mistaken reversal relationship.

Now to the answer choices that need explanation:

Answer (D):
Closed plane figure bounded by straight lines -> polygon
Closed plane figure bounded by straight lines -> polygon

This answer choice is not flawed because the conclusion repeats the premise. The sufficient condition in this case is being a closed plane figure, while the necessary is being a polygon.

Answer (E)
Never lost something they cannot afford to lose -> lax about keeping property secure
Lax about keeping property secure -> never lost anything

This answer concludes that Jon must never have lost ANYTHING, which is not the same as never losing something he cannot afford to lose. The wording is too strong and the stimulus doesn't make this error.

Answer (A):
Have dog -> Know true value of companionship
Know true value of companionship -> have dog

This is a perfect mistaken reversal.




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