Zookeeper: In the historical record, there are both examples of striped nose – tailed mongooses and examples of nose – tailed mongooses that are of a single solid color. However, to my knowledge every living nose – tailed mongoose is striped. Therefore, the mongooses living in the New Delhi Zoo are striped. In the first column below, select that statement that weakens the second sentence in the argument above. In the second column below, select an assumption that must be made to draw the conclusion in the argument above. Make only two selections, one in each column.

MGMAT Official Solution: This question draws on your Critical Reasoning skills—your ability to analyze an argument. First, you are asked for a statement that would weaken the second sentence in the argument. The second sentence reads "However, to my knowledge every living nose-tailed mongoose is striped." What would weaken this claim?: Evidence that there are (or may be) some living nose-tailed mongoose who are not striped. The only answer choice that fits this model is the third one: "Two of the nose-tailed mongooses living in the Brooklyn Zoo are solid grey in color." As for the second column, you're looking for a necessary assumption for the argument—that is, an assumption that you must make in order to draw a valid conclusion. The conclusion of the argument is the final sentence: "Therefore, the mongooses living in the New Delhi Zoo are striped." There is a gap in this argument between "nose-tailed mongooses" in the second sentence and "mongooses" in the conclusion (it's possible that the mongooses in New Delhi aren't nose-tailed). A correct answer will close that gap, stating that all the mongooses in the New Delhi zoo are nose-tailed. The fourth choice does just that: "there is no mongoose living in the New Delhi Zoo that is not nose-tailed" (i.e., they are all nose-tailed). Framing the assumption in the negative is a common feature of correct answers for assumption questions. First column: The correct answer is (C). Second column: The correct answer is (D).

(1st) Striped NT vs Solid NT (2nd) Liv. NT -> Striped (3rd) Liv. Delhi -> Striped To Weaken 2nd: To weaken A->B, by A-/>B or the Mere Coincidence trick Liv. NT -> Solid "Two of the nose-tailed mongooses living in the Brooklyn Zoo are solid grey in color." => Assumption for 3rd: NT is missing as a conditioning/assumption in 3rd. We have to assume that all mongoose living in the Delhi zoo are NT =>

Zookeeper: In the historical record, there are both examples of stripe : Two-part Analysis (TPA)

Weakens Second Sentence	Must Be Assumed
		More than one living mongoose is nose-tailed.
		Not all striped living mongooses are nose-tailed.
		Two of the nose-tailed mongooses living in the Brooklyn Zoo are solid grey in color.
		There is no mongoose living in the New Delhi Zoo that is not nose-tailed.
		Not every striped mongoose living in the New Delhi Zoo is nose-tailed.
		Some mongooses living in the New Delhi Zoo are neither striped nor nose-tailed.

Zookeeper: In the historical record, there are both examples of stripe

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