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# Match flaws | Worked example

Watch a demonstration of one way to approach matching flaw questions. Created by Sal Khan.

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• Honestly, I can't pay attention because of the guy teaching them. He has no flow and gives you now chance to answer on your own. Khan academy, can we please update? It's not beneficial how it's taught.

(A) This recipe will turn out only if one follows it exactly and uses high quality ingredients. Thus, Arthur must have used high-quality ingredients.

(B) If a computer has the fastest microprocessor and the most memory available, it will meet Aletha's needs this year. This computer met Aletha's needs last year. So it must have had the fastest microprocessor and the most memory available last year.

(C) If cacti are kept in the shade and watered more than twice weekly, they will die. This cactus was kept in the shade, and it is now dead. Therefore, it must have been watered more than twice weekly.

(D) A house will suffer from dry rot and poor drainage only if it is built near a high water table. This house suffers form dry rot and has poor drainage. Thus, it must have been built near a high water table.

(E) If one wears a suit that has double vents and narrow lapels, one will be fashionably dressed. The suit that Joseph wore to dinner last night had double vents and narrow lapels, so Joseph must have been fashionably dressed.
• why is choice E not a match? It still isn't clear to me.
• If you break down the original statement into a formula then it will look like this: If A + B = C then C + B = A
The Original Statement Setup: (A) well-publicized + (B) Established Author = (C) Successful book.
Conclusion: (B) Julia is well established and (C) the book was successful so (A) it must have been well publicized.

Answer E:(A) Double Vents + (B) Narrow lapels = (C) Fashionably dressed.
Conclusion: He wore (A) double vents and (B) narrow lapels so (C) he was fashionably dressed.

E goes from A + B = C to A + B = C instead of changing to B + C = A. So the format is wrong because it isn't committing the same flaw the A committed.
• Did Sal diagram answer choice (A) correctly?

Because of the "only if," shouldn't (A) should be diagrammed as turn out --> follows exactly + high quality ingredients? The "only if" signals a necessary condition; it's necessary for one to follow a recipe exactly and use high quality ingredients for the recipe to turn out but not sufficient for it to turn out.

If this is true, then answer choice (A) is wrong because it contains two necessary conditions (unlike the stimulus) and because it is technically a valid conclusion.

• Hello! The first two statements of choice C matches the stimulus, but I don't believe its conclusion does. Would you please mind explaining this to me? Thank you.
(1 vote)
• For Choice B it was stated that it is incorrect because it stated that the conclusion presents the the premises had to be true which is in violation for the correct type of flaw within the passage, however, could it further be stated that it may also be wrong as it is also attributing a present situation being aletha's needs this year by contributing to a previous status or condition of last year? In other words may the fact that it is addressing two different points in time whereas the presented article is not also invalidate this choice as a potential answer?
(1 vote)
• Statement: A book tour will be successful if it is well published and the author is an established writer.
Example: If cacti are kept in the shade and watered more than weekly, they will die.

Statement: Julia is an established writer, and her book tour was successful.
Example: The cactus was kept in the shade, and it is now dead.

Statement: So her book tour must have been well publicized.
Example: Therefore, it must have been watered more than twice weekly.
(1 vote)