Weakeners make assumptions
Now, regarding your other query that option B makes some assumptions. Again, a good point.
The idea is that almost all weakeners make some assumptions. There are not many weakeners, if you look at OG, which would conclusively disprove the conclusion just by their own. And in this question, we are looking for a weakener only.
Hope this helps
thank you e gmat for deep analysis.
I do not understand the above idea. Pls cite the og questions in which weakeners disprove the conclusion and in which weakener only weaken the conclusion. pls, cite only one question for each case. thank you very much.
I understand that if information shatters an assumption, it disproves the conclusion. if information increases doubt in an assumption, it increase doubt in the conclusion. The first is the destroyer, the second the weakner. both destroyer and weakner are correct answer for weakening question.
is my thinking correct?
Please find below an OG question where weakener doesn't disprove the conclusion. Or, in other words, it would require us to make assumptions to disprove the conclusion.
(Posted on according-to-the-tristate-transportation-authority-making-113718.html
According to the Tristate Transportation Authority, making certain improvements to the main commuter rail line
would increase ridership dramatically. The authority plans to finance these improvements over the course of five
years by raising automobile tolls on the two high-way bridges along the route the rail line serves. Although the
proposed improvements are indeed needed, the authority’s plan for securing the necessary funds should be
rejected because it would unfairly force drivers to absorb the entire cost of something from which they receive no
1.. Which of the following, if true, would cast the most doubt on the effectiveness of the authority’s plan to
finance the proposed improvements by increasing bridge tolls?
(A) Before the authority increases tolls on any of the area bridges, it is required by law to hold public hearings at
which objections to the proposed increase can be raised.
(B) Whenever bridge tolls are increased, the authority must pay a private contractor to adjust the automated
(C) Between the time a proposed toll increase is announced and the time the increase is actually put into effect,
many commuters buy more tokens than usual to postpone the effects of the increase.
(D) When tolls were last increased on the two bridges in question, almost 20 percent of the regular commuter
traffic switched to a slightly longer alternative route that has since been improved.
(E) The chairman of the authority is a member of the Tristate Automobile Club that has registered strong
opposition to the proposed toll increase.
The asnwer is Option D. One very obvious assumption required in this question is that past trends will be followed in the future too.
And below is the OG question where weakener does shatter the conclusion:
(Posted on unlike-the-wholesale-price-of-raw-wool-the-wholesale-price-93250.html
Unlike the wholesale price of raw wool, the wholesale price of raw cotton has fallen considerably in the last Year.
Thus, although the retail price of cotton clothing at retail cloting stores has not yet fallen, it will inevitably fall.
Which of the following, if true, most seriously weakens the argument above?
A. The cost of processing raw cotton for cloth has increased during the last Year.
B. The wholesale price is typically higher than that of the same volume of raw cotton.
C. The operating costs of the average retail cloting store have remained constant during the last year.
D. Changes in retail prices always lag behind changes in wholesale prices.
E. The cost of harvesting raw cotton has increased in the last year.
The answer is Option A.
Since, as per the weakener, the cost of processing raw cotton for cloth has increased during the last Year, we cannot say that "retail price of cotton will inevitably
fall". It might or it might not fall (depends how much processing costs has increased).
As far as your reasoning goes, it is precisely right. Whether a statement increased doubt or shatters the conclusion, in both the cases, it is a weakener.
Hope this helps
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