A series of experiments was conducted in which rats of various ages we

A series of experiments was conducted in which rats of various ages were placed in a series of mazes and timed to see how long it took them to find their way out. In the first set of runs, the younger rats made their way out of the mazes an average of 30 percent faster than the older rats. Three days later, however, when the same rats were placed in the same mazes, the older rats were faster than the younger rats by nearly 40 percent.

Premise: Series of experiments conducted ; Young rats faster than older rats in first set; 3 days later, older rates were faster than the younger rats

Which of the following hypotheses best accounts for the findings of the experiment?

A. A rat’s sense of smell becomes less acute as it gets older --> Incorrect: If so how can we account for the increase in the older rats's speed?

B. The older rats had been used in earlier experiments.-->Incorrect: We only know from the premise that only a first set of runs were conducted. We have no clue about the certainty of earlier experiments.

C. Older rats have a better-developed sensory memory, which allows them to “remember” the mazes three days later.--> Correct: A much probable explanation with respect to the premise.

D. Younger rats become frustrated when faced with repeated dead ends in a maze, while older rats do not.--> Incorrect: How do we know for sure about the presence of dead ends in the maze?

E. Older rats tire more easily than younger rats.--> Incorrect: This is pretty ironical considering the fact that the older rats were faster than the younger rats in the next series of experiments.

Ans : (C)

Official Explanation:

Step 1: Identify the Question Type

The wording of this stem is less direct than most question stems, but any question that asks you to account for a certain set of potentially contradictory findings is an Explain question.

Step 2: Untangle the Stimulus

When untangling the stimulus, paraphrase the given information and make sure you understand the paradox. Indeed, the findings of the experiments described in this stimulus seem to be contradictory: At first it seems that younger rats are capable of completing mazes more quickly, and then it appears that older ones are.

Step 3: Predict the Answer

There could be a couple of reasons why this happened, so it’s difficult to predict the exact answer here. But no matter how the right answer is phrased, you know that it will probably be something about older rats that allows them to perform better the second time around.

Step 4: Evaluate the Choices

If rats develop sensory memories as they get older, this would explain how the older rats, which were initially slower, were later able to complete the mazes more quickly: They “remembered” the route. This is what (C) indicates, so it’s the correct answer. Remember that for an answer choice to be correct, it must relate logically to both parts of the seeming contradiction in the stimulus. All the incorrect choices here explain only one side of the story or the other; in other words, they fail to resolve the paradox. If rats use their sense of smell to negotiate mazes, then (A) might explain why the older rats were slower initially, but it would not explain why they completed the mazes faster three days later. (B) might explain why the older rats finished the mazes faster in the later runs (assuming that the earlier experiments also involved mazes), but it wouldn’t explain why they initially took longer than the younger ones. If (D) were true, you would expect older, more patient rats to finish more quickly every time. (E) might explain why the older rats took longer the first time, but it wouldn’t explain why they finished more quickly the second time. Choice (C) is correct.

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