Summarize Argument
The author concludes that a group of unusual meteorites found in Shergotty, India probably came from Mars. As support, the author says that the structure of the meteorites suggests that they came from Mercury, Venus, or Mars. Any material from Mercury would have been captured by the Sun and any material from Venus would not have escaped into space, which leaves Mars as the likely source of the meteroites.
Describe Method of Reasoning
The author’s argument works by laying out three possible options (Mercury, Venus, and Mars), and eliminating two of the options (Mercury and Venus), leaving Mars as the likely source of the meteorites.
A
offering a counterexample to a theory
The author does not offer a counterexample. Instead, the author outlines a question (the origin of the unusual meteorites) and makes a conclusion about the answer to this question (that the meteorites probably came from Mars).
B
eliminating competing alternative explanations
The author’s argument works by eliminating Mercury and Venus as potential alternate explanations of the origin of the meteorites.
C
contrasting present circumstances with past circumstances
The author does not contrast present circumstances with past circumstances; there is no distinction between how things are now and how things were in the past.
D
questioning an assumption
The author does not question any assumptions. Instead, the author lists Mercury and Venus as two of the possible sources of the meteorites because of the meteorites’ structure, then explains that material from Mercury and Venus would not have reached Earth.
E
abstracting a general principle from specific data
The author does not discuss any general principles, nor does the author mention specific data.
Summary
All people prefer colors that they can easily distinguish. Infants can easily distinguish bright colors, but have difficulty distinguishing subtle shades. Brightly colored toys for infants sell better than toys in subtle shades at the same price.
Strongly Supported Conclusions
Infant toy sales reflect the preferences of infants.
A
Infants prefer bright primary colors to bright secondary colors.
This answer is unsupported. We don’t know from the stimulus whether infants are able to distinguish between primary and secondary colors. We only know that infants are able to distinguish between bright and subtle colors.
B
Color is the most important factor in determining which toys an infant will prefer to play with.
This answer is unsupported. To say that color is the “most important factor” is too strong. Color is an important factor for infants, but we don’t have enough information to conclude that it is the most important factor.
C
Individual infants do not have strong preferences for one particular bright color over other bright colors.
This answer is unsupported. The stimulus addresses the preferences of infants generally. We don’t know about any individual infant’s preferences from the stimulus.
D
The sales of toys for infants reflect the preferences of infants in at least one respect.
This answer is strongly supported. We know that infants prefer bright colors and we know that brightly colored toys sell better. Therefore, it’s likely that this preference for bright colors affects the toy sales for infants.
E
Toy makers study infants to determine what colors the infants can distinguish easily.
This answer is unsupported. Nothing in the stimulus addresses the toy maker’s perspective.
Summary
The government is considering approving a synthetic hormone, BST, for use in dairy cows. BST increases milk production, but also leads to several adverse side effects for dairy cows. The side effects can be controlled with constant veterinary care, but constant care would cost big farms far less per dairy cow than small farms.
Strongly Supported Conclusions
If the BST hormone is approved, big farms could gain more benefits from its approval compared to small farms.
A
The government is unlikely to approve the synthetic hormone BST for use in cows.
We don’t know whether the government is unlikely to approve BST. We only know that the government is considering its approval, not that the government would actually approve or disapprove the hormone.
B
The proportion of cows that suffer from udder inflammation, decreased fertility, and symptoms of stress is currently greater on big dairy farms than on small ones.
We don’t know whether the proportion of cows that suffer from adverse side effects is greater on big farms compared to small farms. We know that BST leads to adverse side effects, but we do not know if any cows are currently suffering.
C
At the present time milk from cows raised on small farms is safer to drink than milk from cows raised on big farms.
We don’t know whether milk produced from small farms is safer to drink compared to milk from big farms. The stimulus does not address whether BST affects the safety level of consuming milk the dairy cows produce.
D
The milk from cows who receive BST will not be safe for people to drink.
We don’t know whether milk from cows who receive the BST hormone would be unsafe to drink. The stimulus does not address whether BST affects the safety level of consuming milk the dairy cows produce.
E
Owners of big farms stand to gain more from government approval of BST than do owners of small farms.
If the constant veterinary care for the cows will cost big farms less per cow than small firms, then big farms could gain more benefits from governmental approval of BST since cows treated with BST produce more milk.
Summarize Argument: Counter-Position
The author believes that a recent article was incorrect when it claimed that there is no evidence the rate of extinction of animal species is increasing; in other words, the author believes that there is evidence that the rate of extinction of animal species is increasing. This position is supported by data on North American fish extinctions, which show more than double the extinctions from 1950-2000 than there were from 1900-1950.
Identify Conclusion
The conclusion is the author’s statement of disagreement with the article authors: “They are wrong.”
A
There is evidence that the rate of extinction of animal species is accelerating.
This accurately rephrases the argument’s conclusion. This is just another way of saying that the author disagrees with the claim that there is no evidence of an accelerating extinction rate.
B
The future rate of extinction of animal species cannot be determined from available evidence.
The author does not make this claim. Whether an exact future extinction rate can be determined is not discussed, the dispute is just over whether or not the rate is increasing.
C
The rate of extinction of North American fishes is parallel to the rate of extinction of all animal species taken together.
The argument is not designed to support this claim. While this might be taken as an assumption the author makes, nothing in the argument gives us a reason to believe that the North American fish extinction rate is representative.
D
Forty species and subspecies of North American fishes have vanished in the twentieth century.
This claim is not supported by the rest of the argument. The author states this number as a fact to help demonstrate the increasing fish extinction rate, but nothing else provides support for the claim of how many fish species have vanished.
E
A substantial number of fish species are in danger of imminent extinction.
The author never claims this to be true. The argument isn’t concerned with how many fish species are likely to go extinct soon, fish are just used as an example to demonstrate a general increase in extinction rates.
Note: J.Y. calls Q24 an MSS (Most Strongly Supported) question. We've since updated the tags for RC to be more precise, and so we now tag Q24 as "Stated," because we're evaluating each answer choice on the basis of whether or not an example is explicitly stated in the passage. That said, you can still reach the right answer if you approach Q24 as MSS. We just think it's more appropriate to call it Stated.