In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear...

GMAT Critical Reasoning : (CR) Questions

Source: Official Guide

Critical Reasoning

Evaluate

HARD

...

Notes

Post a Query

In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars. When, as often happens, a collar slips off, it is put back on. Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart. Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females. Probably, therefore, some substance in the tranquilizer inhibits fertility.

In evaluating the argument, it would be most useful to determine which of the following?

Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park.

How the tranquilizer that is used for immobilizing rhinoceroses differs, if at all, from tranquilizers used in working with other large mammals

How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars

Whether male rhinoceroses in the wildlife park lose their collars any more often than the park's female rhinoceroses do

Whether radio collars are the only practical means that park rangers have for tracking the movements of rhinoceroses in the park

Solution

Passage Analysis:

Text from Passage	Analysis
In a certain wildlife park, park rangers are able to track the movements of many rhinoceroses because those animals wear radio collars.	What it says: Rangers track rhinos using radio collars What it does: Sets up the basic scenario and introduces the tracking system What it is: Background information Visualization: 25-30 rhinos wearing radio collars being tracked by rangers
When, as often happens, a collar slips off, it is put back on.	What it says: Collars frequently fall off and need to be replaced What it does: Introduces a recurring problem with the collar system What it is: Factual detail about collar maintenance
Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart.	What it says: Recollaring requires tranquilizing the rhino first What it does: Explains the process and introduces tranquilizer use What it is: Procedural information Visualization: Rhino being shot with tranquilizer dart → becomes immobile → collar put on
Female rhinoceroses that have been frequently recollared have significantly lower fertility rates than uncollared females.	What it says: Frequently recollared females have much lower fertility than uncollared ones What it does: Presents the key observation linking recollaring to fertility problems What it is: Study finding/observation Visualization: Frequently recollared females: 30-40% fertility rate vs. Uncollared females: 75-80% fertility rate
Probably, therefore, some substance in the tranquilizer inhibits fertility.	What it says: The tranquilizer likely contains something that reduces fertility What it does: Draws a causal conclusion from the fertility observation What it is: Author's conclusion

Argument Flow:

The argument starts with background about rhino tracking, then explains that collars often slip off and need replacement using tranquilizers. It then presents the key finding that frequently recollared females have lower fertility rates, and concludes this must be due to something in the tranquilizer.

Main Conclusion:

Some substance in the tranquilizer dart inhibits fertility in female rhinoceroses.

Logical Structure:

The argument uses correlation as evidence for causation - since frequently recollared females (who get more tranquilizer shots) have lower fertility, the author concludes the tranquilizer must be causing the fertility problems.

Prethinking:

Question type:

Evaluate - We need to think of assumptions underlying the argument and create evaluation scenarios that either strengthen or weaken the conclusion when taken to an extreme

Precision of Claims

The argument makes a precise causal claim that 'some substance in the tranquilizer inhibits fertility' based on the observation that frequently recollared females have significantly lower fertility rates than uncollared females

Strategy

The author concludes that tranquilizer causes lower fertility, but there could be other explanations for why frequently recollared females have lower fertility. We need to think of alternative explanations that could either support or challenge this tranquilizer theory. The key is to identify what information would help us determine if the tranquilizer is really the culprit or if something else is causing the fertility problems

Answer Choices Explained

Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park.

Whether there are more collared female rhinoceroses than uncollared female rhinoceroses in the park. This information about the relative numbers of collared versus uncollared females doesn't help us evaluate whether the tranquilizer causes fertility problems. The argument is about the difference in fertility rates between frequently recollared females and uncollared females, not about the total population sizes. Knowing there are more of one group or the other doesn't tell us anything about what's causing the fertility difference.

How the tranquilizer that is used for immobilizing rhinoceroses differs, if at all, from tranquilizers used in working with other large mammals

How the tranquilizer used for rhinoceroses differs from tranquilizers used with other large mammals. This comparison with other species doesn't help evaluate the argument about rhino fertility. We need information that helps us determine if the tranquilizer is actually causing the fertility problems in rhinos, not how it compares to treatments for other animals. Even if the tranquilizer is different, that doesn't tell us whether it's the cause of the fertility issues.

How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars

How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars. This is the most useful information because it would help us test the causal claim. If tranquilizers are used for other purposes (like medical treatment), we could compare the fertility of females tranquilized for those reasons with completely untranquilized females. If other-purpose tranquilized females also have low fertility, it strengthens the tranquilizer theory. If they have normal fertility, it suggests something else about the recollaring process is causing the problem.

Whether male rhinoceroses in the wildlife park lose their collars any more often than the park's female rhinoceroses do

Whether male rhinoceroses lose their collars more often than females. Information about male collar loss rates doesn't help evaluate an argument about female fertility. The argument is specifically about fertility problems in frequently recollared females, and male fertility isn't part of the comparison. This information is irrelevant to determining whether tranquilizers cause fertility problems.

Whether radio collars are the only practical means that park rangers have for tracking the movements of rhinoceroses in the park

Whether radio collars are the only practical means for tracking rhinoceros movements. Information about alternative tracking methods doesn't help evaluate whether tranquilizers cause fertility problems. The argument assumes collars will continue to be used and focuses on the fertility effects of the recollaring process. Knowing about other tracking options doesn't address the causal relationship between tranquilizers and fertility.

Rate this Solution

Tell us what you think about this solution

...

Forum Discussions

Start a new discussion

Post

Previous Attempts

Loading attempts...