Carcass wrote:
Explanation
The passage’s argument makes a case for the painting’s being an authentic van Gogh self-portrait; it cites as evidence the fact that the canvas’s painted-over image is that of a woman who appears in other van Gogh paintings. This argument assumes that another artist would not have painted over the original image of the woman, so the correct answer is Choice C. Since the argument does not depend upon the painting’s stylistic elements or upon the commonalities between this and other van Gogh paintings, Choices A and B are incorrect. Choices D and E establish criteria for attribution beyond the passage’s argument, so they are incorrect as well.
I’m going to employ the methods from David Kiloran’s
PowerScore Logical Reasoning Bible.
First you need to understand that the category belongs to the
Justify the Conclusion group.
That said you need to break down the relevant premises and the conclusion.
Premise 1:
Either van Gogh or another painter covered the first paintingIn logical notation we denote “van Gogh painted the painting” as
V and another “painter painted the painting” as
P.
Thus the logical notation for Premise 1 is:
P —> V
V —> PThese are logical equivalent since they are contrapositives.
Conclusion:
Because the face of the woman in the underimage also appears on canvases van Gogh is known to have painted, the surface painting must be an authentic self-portrait by van GoghLet “Woman in the under image also appears on canvases van Gogh is known to have painted” as
W and “the surface painting must be an authentic self-portrait by van Gogh” is equivalent to “van Gogh painted the painting” so it is also
VThus the logical notation for Conclusion is:
W —> VSo in summary we have:
P1:
P —> V;
V —> PC:
W—> VWe need another premise
P2 that allows us to go from
P1 to
C.
The only premise that allows us to do this is
W—>P because
W—>P +
P —> V =
W—>P —> V =
W —> V which is the conclusion
C.
The only answer that has
P2 is Answer choice C which is the logical contrapositive of
P2:
“Any painted canvas incorrectly attributed to van Gogh would not contain an underimage of a subject that appears in authentic paintings by that artist.”
This is essentially saying
P—>W which equals
W—>P.
Although it may seem complicated based on what I wrote. If you understand the method and now how to break down the problem into logical steps you can breeze through this problem in about 30 seconds. I highly recommend that PowerScore book. It requires a learning curve to learn the logic, but the payoff is immense in terms of learning to dealing with any CR problem efficiently and easily.