1. The Police Commissioner's proposal hopes to decrease the number of crimes in
city Y by shifting police officers from low-crime to high-crime districts. His
proposal is based on data that demonstrate that crime decreases when
additional police officers are moved into a district. However, the data do not
mention anything about the effect on the districts from which the police officers
were removed. The commissioner's plan is based on the assumption that the
movement of police officers will not have any adverse effects on the low-crime
districts.
(A) While it is encouraging that a similar plan worked successfully in City X, this
fact is certainly not essential for the success of the plan in City Y. The cities may
be so different as to make the comparison meaningless.
(B) The police commissioner's proposal is focused solely on decreasing the
number of crimes in city Y. The severity of the crimes has no bearing on whether
the commissioner's proposal will succeed or not.
(C) The actual numerical distinction between high and low-crime areas of the city
is immaterial to the commissioner's proposal. For instance, if the number of
crimes committed in all high crime districts was only double (instead of more than
triple) the number of crimes committed in low crime districts, the proposal could
still be valid.
(D) It would be practically beneficial to the commissioner's plan if there were
more low crime than high crime districts in city Y. This would enable the
movement of police officers to every high crime district. However, this is not
necessary to achieve the commissioner's goal of decreasing the total number of
crimes in city Y. Even if there were more high-crime districts than low-crime
districts in city Y, police officers could still be shifted to some (though not all)
high-crime districts, and thereby possibly reduce the total number of crimes in
city Y.
(E) CORRECT. The police commissioner's proposal would not make sense if
districts of the city from which police officers are removed experience significant
crime increases shortly after the removal of those officers. This would at least
partially, if not fully, negate the reduction in the number of crimes in the highcrime districts.
This choice establishes that, in fact, the low-crime districts do
NOT suffer from significant crime increases after the removal of some officers--
an essential assumption upon which the commissioner's proposal depends.

2. The argument concludes that rising sea levels caused by global warming will
destroy major coastal population centers and displace millions of people. Any
assumption in support of this conclusion would have to corroborate that these
events will definitively take place.
(A) CORRECT. If new technological developments in the next century allow
people to divert rising seas from the world’s cities (i.e., population centers), cities
will not be destroyed and millions of people will not be displaced. Thus, a
necessary assumption is that these technologies will not be developed.
(B) A simple awareness of the steps to reduce emissions in no way undermines
the argument’s conclusion, as this answer choice does not describe any action
being taken by individuals. Additionally, greenhouse gases are never mentioned
as the primary by-product of human activity that causes global warming, and are
therefore not sufficient to address the argument.
(C) The argument never suggests that all coastal population centers are similarly
affected; this choice is too extreme and overreaching for the argument’s
conclusion.
(D) This might be true, but it is not an assumption on which the conclusion rests.
Instead, this answer choice is simply an inference that might be drawn from the
premises.
(E) The idea that human activity is the sole cause of global warming is neither
suggested nor assumed by the argument. In addition, the wording "sole cause" is
too extreme.

3. As an advertisement, this passage attempts to entice the reader into purchasing
a new HitItFar driver by touting its benefits, both implied or explicit. The key to
answering this question is to be able to analyze each claim to determine whether
it is implied, explicitly stated, or neither.
(A) By asking the reader rhetorically "isn't it time you added power ... and
distance ... [by switching to the HitItFar driver]?", the advertisement implies that
the use of the club will add "power ... and distance" and, hence, will improve
one's play.
(B) CORRECT. The advertisement states that the 12 major championships
winner have recently switched to the new driver. There is nothing in the passage
to imply that any of them were using the driver at the time of their victories;
hence, this claim is neither implied, nor made explicitly, in the passage. (C) It is a
reasonable assumption that professional golfers, particularly those
skilled enough to win a major championship, are experts and know what
constitutes a great club. The advertisement makes this implication and reinforces
it by citing the recent decision of these golfers to switch to the HitItFar driver; this
provides an implicit expert endorsement for the HitItFar driver.
(D) The point of the advertisement is to prompt the reader into purchasing a new
driver to replace his or her old driver in order to "add power and distance"; this
implies that the new driver is superior to the reader's existing driver.
(E) This claim is explicitly stated in the first sentence of the passage.

4. The researchers claim that Delta-32 prevents its carriers from contracting the
Plague. They support this claim by noting that a strikingly large percentage of
descendants of Plague survivors carry the mutation. We are asked to find an
assumption underlying the claim.
(A) The argument is specific to the relationship between Delta-32 and resistance
to the Plague. Other diseases are irrelevant.
(B) Again, the argument is specific to the relationship between Delta-32 and
resistance to the Plague. Other diseases are irrelevant.
(C) Delta-32 may have existed in its current form before the sixteenth century
and the merit of the argument would not change.
(D) The argument does not claim that Delta-32 prevents all bacteria-caused
disease.
(E) CORRECT. The researchers claim that Delta-32 prevented its carriers from
contracting the Plague on the basis of its presence in descendants of Plague
survivors. But it is theoretically possible that these descendants carry the
mutation Delta-32 because the Plague mutated the genes of their ancestors. In
order to claim that the mutation prevented the Plague, we must assume that the
Plague did not cause the mutation Delta-32.

5. The author concludes that one will only be able to determine the age of a
Brazilian ash by counting its rings if the temperature in the tree's environment
never exceeds 95 degrees Fahrenheit. The author bases this conclusion on the
fact that the tree loses rings when the temperature exceeds that level. However,
if the number of rings lost by a Brazilian ash at high temperatures can be
predicted, it may be possible to determine the age of a tree even if the
temperature exceeds 95 degrees. (A) The argument says nothing about precipitation.
This answer choice is out of scope since it would require a number of other assumptions
to make it relevant to the argument's conclusion.
(B) Whether other trees share this feature is irrelevant; the argument focuses
only on the Brazilian ash.
(C) The number of days of excessive heat needed to cause the tree to lose rings
is irrelevant.
(D) The thickness of the rings is irrelevant.
(E) CORRECT. The conclusion is that the rings will be a reliable measure only if
the temperature never exceeds 95 degrees. This is true only if there is no way to
predict how many rings would be lost when the temperature does exceed 95
degrees. (If it were possible to predict this, one might be able to assess the age
of a tree using its rings even if the temperature had exceeded 95 degrees.)

6. The conclusion of this argument is that the national identification system (“using
licenses for purposes not directly related to operating a motor vehicle”) is unAmerican.
The basis for this claim is that such a system would allow the
government to restrict the liberty of its people. The necessary assumption is one
that connects restrictions on liberties to the concept of “un-American” policies.
(A) The author never mentions future presidential elections, or the role of the
president in such a national identification system. Therefore, the conclusion that
the national identification system is un-American does not depend on this
assumption.
(B) Whether the government will soon, or will ever, start curtailing the activities of
dissidents is irrelevant to this argument: that the national identification system is
un-American simply because it restricts the liberties of U.S. citizens. Even if the
government does not abuse the power the national identification system
provides, the system could still be considered un-American.
(C) CORRECT. This choice connects the concept of "un-American" policies to
restrictions on liberties, essentially defining blanket restrictions on citizens as unAmerican.
(D) Whether Americans are willing to give up their right to travel freely is
irrelevant to this argument: that the national identification system is un-American
simply because it restricts the liberties of U.S. citizens. Even if Americans were willing to
give up their right to move about without identification, the system could
still be considered un-American.
(E) While the author may be inclined to agree that Americans should resist the
government regulation of their lives that the national identification system
represents, this argument does not depend on such an assumption. In fact, the
author makes a distinction between the national identification system and
“licenses for purposes…directly related to operating a motor vehicle,” so it is
possible that the author considers some government regulation reasonable.

7. The argument presents the facts of an apparent change in a magazine's cover
features since the new publisher took control. While a gossip columnist hailed the
change, newspaper editorials disagreed and concluded that the publisher
favored profit over reporting. The editorials are the opponents of the gossip
columnist; since their conclusion is about the publisher’s desires, there must be
an assumption connecting the publisher to the covers.
(A) This choice is irrelevant, as it is not connected to the conclusion. The
activities of celebrities have nothing to do with the publisher’s interests.
(B) CORRECT. Since the conclusion concerns the publisher’s desires based on
the content of the magazine covers, the editorials have to assume that the
publisher decides who is to be a cover subject. If not, there is no connection
between the covers and the publisher’s interests.
(C) This choice is the opposite of a necessary assumption. For the editorials to
conclude that the publisher prefers profits to reporting, they have to assume that
the two are mutually exclusive.
(D) “Some” means “at least one,” so this is not a powerful statement in any
direction. Furthermore, even if several such stars were running for political office,
it is not at all necessary to assume that to conclude that the publisher was more
interested in profits.
(E) This choice is not correct. While it is true that the editorials must assume
model and movie star covers are likely to sell more copies, it does not have to be
assumed that such covers will result in the sale of triple the number of copies, or
any other specific number.

8. The conclusion of the argument is that renewable sources of energy, chiefly solar
and wind, will be less risky for certain utilities than nonrenewable sources, such
as oil and gas. The basis for this claim is that the renewable sources will provide
stable, low-cost supplies of energy, whereas the prices for nonrenewable sources
will fluctuate according to availability. We are asked to find an
assumption underlying this argument. In order for this argument to be valid, it
must in fact be true that these renewable sources of energy will provide stable,
low-cost supplies.
(A) The utility companies' claim has to do with the supply risk of the new energy
sources, not with how these sources are received by the public.
(B) If no new supplies of traditional energy sources are found, then it is true that
perhaps these nonrenewable supplies will continue to fluctuate in price in a risky
manner. However, the argument does not depend upon any assumption about
the future discovery of oil and gas supplies.
(C) CORRECT. If we assume that weather patterns are consistent and
predictable, then with the stated premises, we can conclude that solar and wind
power will be less risky than oil and gas. If, on the other hand, weather patterns
are not consistent and predictable, then solar and wind power are not reliable
and thus will not provide "stable energy supplies at low cost." Thus, the
argument's conclusion directly depends on this assumption.
(D) To reach the required conclusion, it is not necessary to assume that the
conversion technology for new sources is not more expensive than the present
technology.
(E) This choice does not directly affect the argument. Whether or not energy
produced through combustion can be made less risky, the new energy sources
might still be less risky than the older sources.

9. We are given two premises based on survey results: first, vanilla is the bestselling
flavor of ice cream and, second, those who prefer chocolate usually don't
order vanilla. The author concludes that vanilla-flavored candy should sell better
than chocolate-flavored candy. The author bases this conclusion on the
assumption that it is valid to extend the survey's results beyond ice cream to
include candy.
(A) As a stand-alone, this choice makes common sense but, in the argument, it
would undermine the author's conclusion. We are asked to find an assumption
upon which the author relies, which means the correct assumption should
support the author's conclusion.
(B) This choice is either irrelevant at best (the survey does not address children
specifically) or would undermine the author's conclusion, at worst. We are asked
to find an assumption upon which the author relies, which means the correct
assumption should support the author's conclusion. (C) Preferences for flavors
neither vanilla nor chocolate are outside of the scope of this argument.
(D) This choice addresses only ice cream preferences; it does not provide any
information to tie ice cream preferences to candy preferences.
(E) CORRECT. This assumption supports the author's conclusion by tying ice
cream preferences directly to candy preferences.

10. The conclusion of the argument is that the media are wrong in saying that the
economy is entering a phase of growth and prosperity. The basis for that claim is
that the number of people filing for bankruptcy has increased every month for the
last six months and that bankruptcy lawyers are busier than they have been in
years. In order for this argument to be valid, however, the author has to assume
that the increase in the number of bankruptcies is a result of the state of the
economy and not the result of something unrelated.
(A) This statement does not have to be true for the claim that the media are
wrong about the economy to hold. Even if unemployment rates are useful
indicators of growth and prosperity, the media could still be wrong about the
economy (e.g., if there are other indicators that show problems in other areas).
(B) This does not have to be true for the conclusion to hold. Productivity could
be a good measure of economic growth, but the media could still be wrong about
the economy (e.g., if there are other indicators that show problems in other
areas).
(C) CORRECT. This has to be true for the conclusion to hold. If legislation has
recently been passed that makes it easier to obtain bankruptcy, then the
evidence cited would be less relevant. The increased number of bankruptcies
could have been the result of the easier process rather than of a poor economy.
(D) This does not have to be true for the conclusion to hold. An increase in the
number of bankruptcy lawyers would not explain the increase in the number of
bankruptcy filings.
(E) This does not have to be true for the claim that the media are wrong about
the economy to hold. Even if the media did not often misrepresent the current
state of economic affairs, the argument that the media are wrong might still hold.