Friday 23 January 2015

Assumption Questions

Which of the following is an assumption must for the argument to hold true?



Answer is a presupposition- a statement that is a must if the argument is true. Without that assumption, argument falls apart- it
is an unstated premise. You ABSOLUTELY NEED an assumption. If you don't have an assumption, then the argument dies.

• Stimulus will always be an argument- since you can only strengthen a conclusion, not a fact set. Identify, isolate and assess
the premises and conclusion
• Focus on conclusion
• Information in stimulus is suspect. Reasoning errors are present which can be corrected by answer choice.
• Strong prephrases possible
• Answer choices can bring new information which is not present in stimulus.
Assumptions are NECESSARYfor the argument – author relies upon it, and is fully committed to it.
Assumptions are NEVERstated in the argument – if it is directly mentioned, it is not an assumption.
Assumption is a minimalist answer- if it has any information author is not committed to or sure of it will not be correct.
How Assumption Questions are different from Must be true questions? – Assumption is something that must be true BEFORE
the argument.


Incorrect Answer Choices:



1. No tie to the conclusion- uses words from conclusion and is broadly related, but is not an assumption necessary for the
argument. A sub set is 'breaks up a category'- assumption talks of boys and girls vs. teachers, and answer choice talks of
boys vs. girls
Opposite answer- were this to be assumed, argument will be weakened! It is important for this not to be true for conclusion
to be correct!
Switching terms- shell game

2. Addresses premises only
Follows on from the conclusion, instead of conclusion following on from it.
Too broad – e.g. instead of cyclists, comment about athletes. This doesn't HAVE to be true! An assumption has to be 100 %
true
Type of Assumptions: Supporter/Defender

3. Supporter: Traditional linking role- links two part of premises, or premise to conclusion. Conclusion in such an argument
will have some new element which is not present in premises. In an assumption question, always be on lookout for a gap
in the argument premise and conclusion- a new element, and then the answer choice that brings that new element in
picture would be a straight win.

4. Defender: protect the argument by eliminating ideas that could weaken the argument. In order to believe that his
argument is correct and fool-proof, the author is assuming that all possible objections have been considered and rejected.
This can be an infinite range of assumptions.
If confused between some answer choices, use ASSUMPTION NEGATION TECHNIQUE

5. Converts an assumption question to a weaken question- negate both the assumption answer choices, the one whose negation causes
the entire argument to fall is the correct answer choice. This will happen because of necessary, indispensable nature of assumption.


Negation:

Is logical negation, not polar opposite. 'I went to beach every day' negated is 'I didn't go to beach every day', not 'I didn't go to
beach any day' (polar opposite)

Logical opposite of sweet is not sweet (not sour). Logical opposite divides the subject under consideration into two sets which
include all possible states.

Logical opposite of all – not all (not none); logical opposite of none is some. If all is 100, not all is 0-99. None is 0, and some is 1-100

Logical opposite of none- at least one.

You can use not necessarily for negating in most cases.


Some patterns observed in GMAT:

• At least one or at least some: When an assumption answer choice starts with these, it is normally correct. Negate and test –
none.
Constructions which claim to be most important/primary consideration/ main factor are normally wrong.
Look out for constructions with not/negative etc. they might be correct.

Assumptions and Causality



• Author assumes no other cause exists
• Author assumes cause always leads to effect
• Author assumes that when cause doesn't occur effect doesn't occur
• Eliminates the possibility that stated relationship is reverse
• Eliminates possible problems with data


In a cause- effect relationship argument, choose an assumption which supports this causal relationship in one of the above
5 ways. Answer choices discussing matters before or after the causal relationships are not correct.

In a fill in the bank question stem beginning with a premise indicator like 'because_______ or as a result of _____' you have to
provide an assumption. Beginning with conclusion indicator- 'therefore ______' you have to provide a must be true/main point
answer.

GMATPREP EXAMPLES



Q. If a person chooses to walk rather than drive, there is one less vehicle emitting pollution into the air than there would be
otherwise. Therefore if people would walk whenever it is feasible for them to do so, the pollution will be greatly reduced. Which
of the following is an assumption on which the argument depends?

A) Cutting down on pollution can be achieved in a variety of ways.
B) Taking public transportation rather than driving is not always feasible
C) Walking is the only feasible alternative to driving that results in reduction in pollution
D) There are people who never drive but who often walk
E) People sometimes drive when it is feasible to walk instead
[Reveal] Spoiler:


Q. A famous singer recently won a lawsuit against an advertising firm for using another singer in a commercial to evoke the
famous singer's well-known rendition of a certain song. As a result of the lawsuit, advertising firms will stop using imitators
in commercials. Therefore, advertising costs will rise, since famous singers' services cost more than those of their imitators.
The conclusion above is based on which of the following assumptions?

(A) Most people are unable to distinguish a famous singer's rendition of a song from a good imitator's rendition of the same
song.
(B) Commercials using famous singers are usually more effective than commercials using imitators of famous singers.
(C) The original versions of some well-known songs are unavailable for use in commercials.
(D) Advertising firms will continue to use imitators to mimic the physical mannerisms of famous singers.
(E) The advertising industry will use well-known renditions of songs in commercials.
[Reveal] Spoiler:


"ASSUMPTION" SET




1. To decrease the number of crimes in city Y, the city's Police Commissioner proposed taking some police officers
from low-crime districts of the city and moving them to high-crime districts of the city. His proposal is based on city
Y crime data that show that the number of crimes in any district of the city decreases when additional police
officers are moved into that district. The Police Commissioner's proposal depends on which of the following
assumptions?

• City X experienced a drastic reduction in crime after implementing a proposal similar to that proposed by the Police
Commissioner of city Y.
• The severity of crimes committed in any district of the city decreases when additional police officers are moved
into that district.
• The number of crimes committed in all high-crime districts of city Y is more than triple the number of crimes
committed in all low-crime districts of city Y.
• There are more low-crime districts than high-crime districts in city Y.
• Districts of the city from which police officers are removed do not experience significant crime increases shortly
after the removal of those officers.

2. Although there has been great scientific debate for decades over global warming, most scientists now agree that
human activity is causing the Earth's temperature to rise. Though predictions vary, many global warming experts
believe that average global temperatures will rise between three and eight degrees Fahrenheit during the next
century. Such an increase would cause an alarming rise in sea levels, displacing millions of people by destroying
major population centers along the world's coastlines. Which of the following is an assumption in support of the
argument's conclusion?

• New technological developments in the next century will not divert rising seas from the world's coastal cities.
• Individuals will not become more aware of the steps they can take to reduce the emission of greenhouse gases.
• Rising sea levels similarly affect all coastal population centers.
• Some global warming experts predict a greater than eight degree Fahrenheit increase in global temperatures
during the next century.
• Human activity is the sole cause of increasing global temperatures.

3. "The new HitItFar driver is the only golf club that uses space-age Titanium-Kryptonium alloy to strengthen its head.
This driver is SO good, the last 12 winners of the major tour championships have all recently switched to it! Isn't
it time for you to add power to your swing and distance to your drives? Trade in your old driver today — and
HitItFar tomorrow!" All of the following claims are either implied or made explicitly in the above advertisement
EXCEPT:

• Switching to the HitItFar driver will improve your play.
• The HitItFar driver helped the last 12 major championship winners achieve their victory.
• Major championship winners are experts and know what constitutes a great golf club.
• Your existing driver is inferior to the HitItFar driver.
• Only HitItFar golf clubs have Titanium-Kryptonium alloy in the head of their drivers.

4. Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived
the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria
that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the
direct descendants of the residents of an English town where an unusually large proportion of people survived the
Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times
higher than that found in other locations. The researchers' hypothesis is based on which of the following assumptions?

• Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
• The Plague is not similar to other diseases caused by bacteria.
• Delta-32 did not exist in its current form until the sixteenth century.
• No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
• The Plague does not cause genetic mutations such as Delta-32.

5. The popular notion that a tree's age can be determined by counting the number of internal rings in its trunk is
generally true. However, to help regulate the internal temperature of the tree, the outermost layers of wood of the
Brazilian ash often peel away when the temperature exceeds 95 degrees Fahrenheit, leaving the tree with fewer
rings than it would otherwise have. So only if the temperature in the Brazilian ash's environment never exceeds 95
degrees Fahrenheit will its rings be a reliable measure of the tree's age. Which of the following is an assumption
on which the argument above depends?
• The growth of new rings in a tree is not a function of levels of precipitation.
• Only the Brazilian ash loses rings because of excessive heat.
• Only one day of temperatures above 95 degrees Fahrenheit is needed to cause the Brazilian ash to lose a ring.
• The internal rings of all trees are of uniform thickness.
• The number of rings that will be lost when the temperature exceeds 95 degrees Fahrenheit is not predictable.

6. The Department of Homeland Security has proposed new federal requirements for driver's licenses that would
allow them to be used as part of a national identification system. Using licenses for purposes not directly related
to operating a motor vehicle is un-American because it would require U.S. citizens to carry the equivalent of
"papers." Such a requirement would allow the government to restrict their movements and activities in the manner
of totalitarian regimes. In time, this could make other limits on freedom acceptable. The author assumes which of
the following?

• The next presidential election will be dishonest, as has happened in eastern European countries.
• The government will soon start curtailing the activities of those it considers "dissidents."
• Blanket restrictions on law-abiding individuals are contrary to the traditions of American culture and law.
• The majority of Americans are not willing to give up their right to travel and move about without identification.
• Americans should resist all government regulation of their lives.12

7. Since the new publisher took control, a news magazine's covers have featured only models and movie stars.
Previously, the covers had displayed only politicians, soldiers, and business leaders. A leading gossip columnist
claimed that the changes made the magazine relevant again. However, many newspaper editorials disagreed and
suggested that the new publisher is more interested in boosting sales than in reporting important news events.
Which of the following is an assumption necessary for the argument made by the gossip columnist's opponents?

• The charitable activities of models and movie stars often focus public attention on pressing problems.
• Final authority for choosing the cover subject of the magazine lies with the publisher.
• A magazine can boost sales while highlighting the coverage of important world leaders.
• Some of the movie stars featured are now running for political office.
• Magazine issues with models or movie stars on the covers are purchased at a rate more than three times greater
than is the case with issues featuring politicians on the covers.

8. In response to the increasing cost of producing energy through traditional means, such as combustion, many utility
companies have begun investing in renewable energy sources, chiefly wind and solar power, hoping someday to
rely on them completely and thus lower energy costs. The utility companies claim that although these sources
require significant initial capital investment, they will provide stable energy supplies at low cost. As a result, these
sources will be less risky for the utilities than nonrenewable sources, such as gas, oil, and coal, whose prices can
fluctuate dramatically according to availability. The claim of the utility companies presupposes which of the following?

• The public will embrace the development of wind and solar power.
• No new deposits of gas, oil, and coal will be discovered in the near future.
• Weather patterns are consistent and predictable.
• The necessary technology for conversion to wind and solar power is not more expensive than the technology
needed to create energy through combustion.
• Obtaining energy from nonrenewable sources, such as gas, oil and coal, cannot be made less risky.

9. Surveys consistently show that the best-selling ice cream flavor is vanilla, although those who prefer chocolate
rarely order vanilla. Vanilla-flavored candy, then, probably sells better than chocolate-flavored candy. Which of
the following is an assumption upon which the author of the argument relies?

• Because someone prefers vanilla ice cream does not mean he prefers vanilla-flavored candy.
• Children who prefer vanilla ice cream also tend to like chocolate candy.
• Those who prefer neither vanilla nor chocolate ice cream also prefer other flavors of candy.
• Someone who prefers vanilla ice cream may still order chocolate on occasion.
• Preferences for certain ice cream flavors are similar to preferences for candy flavors.

10. The media claim that the economy is entering a phase of growth and prosperity. They point to lower unemployment
rates and increased productivity. This analysis is false, though. The number of people filing for bankruptcy has
increased every month for the last six months, and bankruptcy lawyers report that they are busier than they have
been in years. Which of the following is an assumption on which the argument depends?

• Unemployment rates are not useful indicators of growth and prosperity.
• Economic growth cannot be measured in terms of productivity.
• Legislation has not been recently passed to make legal bankruptcy easier to obtain.
• There has not been an increase in the number of bankruptcy lawyers..
• The media often misrepresent the current state of economic affairs.

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