- Must be true/Inference/Conclusion CR: You have to consider whatever stated in the stimulus as true.
Correct choices can be:
- Paraphrased of some part or entire stimulus
- Combination of two or more premises
Incorrect choices can be:
a. Could
be true or Likely to be true choices
b. Exaggerated/Extreme
case answers
c. New information (not explicitly
mentioned in the stimulus) containing choices
d. Shell game (an idea, in one of the
choices, similar to the one mentioned in the stimulus, but in a modified form
to make it attractive choice. This will be a Trap)
e. Opposite answer (opposite to the stated
facts in the stimulus). For example, stimulus shows case >>> effect
while the choice says effect >>> cause.
f. Reverse order (rearrangement of some
term in the answer choices which are also mentioned in the stimulus). For
example,
Many politicians are having some
type of security gadgets.
While the choice says:
Some politicians are having many
types of security gadgets.
- Main Point Question: It is same as the Must be True/Inference types. You have to consider whatever stated in the stimulus as true but the correct choice reflects the author’s point of view and all facts in this choice are also reflected in the stimulus.
Incorrect
choices can be:
a. Choices
that repeats one/some of the premise(s) of the argument.
b. Answers
that are true as per the argument but do not capture author’s point.
c. Exaggerated/Extreme
case answers
g. New
information (not explicitly mentioned in the stimulus) containing choices
d. Shell
game
e. Choices
mentioning the opposite answer
f. Choices
in Reverse order
- Weaken the argument/conclusion:
The best part of this type of question is availability of conclusion in
the argument. If you can spot the conclusion then your chances to select
the best among weakening choices will be higher, because you may find
several choices may be weakening the conclusion but there will be one
which is weakening the MOST.
Remember, the following:
a. You
need to question the validity of the argument not the answer choices.
b. In
the question stem you will find words indicating weaken the conclusion:
Weaken, attack, undermine, contradicts,
evidence against, challenge, damage, counter, refute, argue against, cast doubt,
criticize, call into question, etc.
c. There
are traces of flaw/error in the reasoning given in the argument. Read closely
to spot them. This error can help you to select the best choice.
d. Even
if the choice introduces new information, you need to accept them as
correct choices, if they are weakening the conclusion.
e. We
need to call into question the conclusion by showing that the author fails to
address some crucial part/information to arrive at the conclusion. This missed
part is assumption on which the conclusion is based. We are not to destroy the
conclusion, though it can be a correct choice.
f. Try
to personalize the choices as if these are asked to you. What would you answer
for them? This will become easier once you start practice.
Example: All software engineers go
to US. Mr. X went to US. Therefore, Mr. X is a software engineer.
Not necessarily. This is just
oversimplified statement. Mr. X can be a child care activist, who met the
senator in US for some funds. If the argument were,
Only software engineers go to US. Mr. X went to US.
Therefore, Mr. X is a software engineer.
True.
Correct choices can be
identified by:
- Choices indicating incomplete information (new info), which is missed by the author as one of the possibility.
- Improper comparison b/w two things which are altogether different.
Incorrect answer choices: I
call them Fallacies/Traps.
a. Opposite answer: This is almost present
as one of the answer choices. Refer the Must
be True question section for some details. This choice will lead you to
think in the opposite direction w.r.t. the conclusion.
b. Shell game choice: Refer the Must be True question section for some
details. Remember, in shell game, a similar reasoning/idea is presented similar
to one of the premises but it is in a modified form.
c. Out of scope choice: choices which are
not as per the context. For example, the argument is on plant in US while this
choice is on plants in other countries.
Now, lets take an example from OG10
to analyze different types of incorrect weakening choices:
110. Robot
satellites relay important communications and identify weather patterns. Because
the satellites can be repaired only in orbit, astronauts are needed to repair
them. Without repairs, the satellites would eventually malfunction. Therefore,
space flights carrying astronauts must continue.
Which of the following, if true, would most seriously
weaken the argument above?
(A) Satellites falling from orbit because of malfunctions
burn up in the atmosphere.
(B) Although satellites are indispensable in the
identification of weather patterns, weather forecasters also make some use of
computer projections to identify weather patters.
(C) The government, responding to public pressure, has
decided to cut the budget for space flights and put more money into social
welfare programs.
(D) Repair of satellites requires heavy equipment, which
adds to the amount of fuel needed to lift a spaceship carrying astronauts into
orbit.
(E) Technical obsolescence of robot satellites makes
repairing them more costly and less practical than sending new, improved
satellites into orbit.
Conclusion:
Therefore, space flights carrying astronauts must continue.
A choice should call into this conclusion as - space
flights carrying astronauts
must NOT continue.
First thing you need to understand why space flights
carrying astronauts must continue. Is it because the satellites can be repaired
only in orbit by astronauts? Is there any other way the satellites can be
repaired (by robots, technologies such as remote sensing from Earth, etc) or
send new and efficient satellites which are more economical to sending
satellites carrying astronauts.
(A) Satellites falling from orbit because of malfunctions
burn up in the atmosphere. [Out of scope choice.
Although new info but irrelevant to our case. Incorrect]
(B) Although satellites are indispensable in the
identification of weather patterns, weather forecasters also make some use of
computer projections to identify weather patters. [Some details, in fact, are
mentioned in the argument on weather patterns but nothing on the use of
computer projections. This is indeed new info
but it is out of scope to our concern. Incorrect]
(C) The government, responding to public pressure,
has decided to cut the budget for space flights and put more money into social
welfare programs. [All underlined parts are new
info and irrelevant to this case. Incorrect]
(D) Repair of satellites requires heavy equipment,
which adds to the amount of fuel needed to lift a spaceship carrying
astronauts into orbit. [Beware, this is Shell
Game fallacy. Both underlined parts are mentioned in the argument
but there is some modification in their connectivity to mislead the test taker.
Incorrect]
(E) Technical obsolescence of robot satellites makes
repairing them more costly and less practical than sending new, improved
satellites into orbit. [This is what missing as one of the possibilities
against sending satellites carrying astronauts. Correct]
- Cause-Effect Reasoning
- Strengthen and Assumption: Most challenging and frequently
occurring types of questions on GMAT.
Remember the following:
- There will always be one main conclusion present either in argument or in the question stem.
- You need to understand the organization of the argument, premises and conclusion, in order to find the correct answer choices.
- Read the stimulus carefully as there can be reasoning errors/gaps, which are crucial for assumption based questions.
- Even if the choice introduces new information, you need to accept them as correct choices, if they are fitting in the context for the conclusion.
- Assumptions are unstated premises, which connect the premises/facts with the main conclusion, while the Strengthen part provides additional support to the conclusion. You can say Strengthen choices advocate the conclusion.
- This is most critical-You need to consider all the answer choices as correct and the stimulus is in question. Only the metal each choice carry varies. I mean these all may support the argument from 1%-100% but there is only one choice which is strengthening the argument the MOST.
Strengthen
types:
a. The question stem will have indicators such as:
a. The question stem will have indicators such as:
strengthen, support, helps, justifies
Correct choices:
a.
Identify the conclusion and connect the answer choices
with it to answer the question – does this choice helps the author? Is yes,
this is your answer.
b.
While understanding the organization of the argument,
if you find weaknesses/flaws/gaps, which are made intentionally, and one of the
answer choices is removing this problem then its your answer.
c.
If there is conclusion in the question stem then there
are good chances of finding the:
1.
EXCEPT/LEAST Strengthen choices
2.
A missing info (assumption) is asked to support the
conclusion.
Incorrect choices:
a.
Opposite
answers: These answers are just the opposite of strengthening the
conclusion, i.e., these weaken the conclusion.
b.
Shell Game
answers: This type of answer support a conclusion that is similar to, but
slightly different from, the one present in the stimulus. In other words, this
choice will have a similar but slightly different conclusion.
c.
Out of scope:
These are the most common and more in number among the 5 choices. These bring
irrelevant or narrow scope information to the argument.
d.
Paraphrased
premise: One of the premises is represented in a paraphrased form just to
mislead.
Now, take an example from OG10 to analyze different types
of strengthening choices:
60. Since the
routine use of antibiotics can give rise to resistant bacteria capable of
surviving antibiotic environments, the presence of resistant bacteria in people
could be due to the human use of prescription antibiotics. Some scientists, however,
believe that most resistant bacteria in people derive from human consumption of
bacterially infected meat.
Which of the following statements, if true, would most
significantly strengthen the hypothesis of the scientists?
(A) Antibiotics are routinely included in livestock feed
so that livestock producers can increase the rate of growth of their animals.
(B) Most people who develop food poisoning from
bacterially infected meat are treated with prescription antibiotics.
(C) The incidence of resistant bacteria in people has
tended to be much higher in urban areas than in rural areas where meat is of
comparable quality.
(D) People who have never taken prescription antibiotics
are those least likely to develop resistant bacteria.
(E) Livestock producers claim that resistant bacteria in
animals cannot be transmitted to people through infected meat.
Premises: The routine use of antibiotics can give
rise to resistant bacteria capable of surviving antibiotic environments.
Sub-conclusion:
The presence of resistant bacteria in people could be due to the human use
of prescription antibiotics.
Counter Conclusion: Some scientists, however,
believe that most resistant
bacteria in people derive from human consumption of
bacterially infected meat.
In the question stem, the author asked for
strengthening the scientists’ hypothesis.
So, this question type is our category c of Correct
choices section (refer above).
We are asked for the missing link to prove the
hypothesis as the correct
conclusion. Now, let’s check individual answer
choices:
(A) Antibiotics are routinely included in livestock feed
so that livestock producers can increase the rate of growth of their animals.
[This is the missing link. Correct]
(B) Most people who develop food poisoning from bacterially infected meat are treated
with prescription antibiotics. [New information, which is Out of scope answer. Incorrect]
(C) The incidence of resistant bacteria in people has
tended to be much higher in urban areas than in rural areas where meat is of
comparable quality. [Out of scope answer. Incorrect]
(D) People who have never taken prescription antibiotics
are those least likely to develop resistant bacteria. [This is a Shell Game trap.
This option is in negation to above premises and very narrow in scope. Incorrect]
(E) Livestock producers claim that resistant bacteria in
animals cannot be
transmitted to people through infected meat. [It is a case
of Opposite answer. This
is just stating against the scientists’ hypothesis. Incorrect]
Assumption based
questions: Assumption based questions are usually the most
challenging and trickiest questions on GMAT.
Remember the following (Most of the following points are same
as of the Strengthen types):
a.
There will always be one main conclusion present either
in argument or in the question stem.
b.
You need to understand the organization of the
argument, premises and conclusion, in order to find the correct answer choices.
c.
Read the stimulus carefully as there can be reasoning
errors/gaps, which are crucial for assumption based questions.
d.
Even if the choice introduces new information,
you need to accept them as correct choices, if they are fitting in the context
for the conclusion. Remember,
if the new information is present in the answer choices then to qualify for a
correct contender, this info should be a subset of the main statement in the
stimulus. For example – Men (main statement): White men, Black men, small men,
etc (subsets of Men).
e.
Assumptions are unstated premises, which connect the
premises/facts with the main conclusion. This is the most important part of the
stimulus. Thus, assumption will work like either a Supporter or a Defender:
Premise 1, premise 2, assumption, premise 3, conclusion
In this case, it is supporting the premises to
lead to the conclusion.
Premise 1, premise 2, premise 3, assumption, conclusion
In this case, it is supported by the premises to lead
to the conclusion.
Often, new
information is added as assumption in such cases. If you find an answer
choice that contain new info, stop and check whether this new info is in
context and filling some gaps in the argument. If Yes, then that is your
correct answer.
The author reasoning must be air-tight and every possible
objection has been considered and rejected. It means the idea that can weaken
the conclusion is already addressed in the stimulus or cannot occur. Here comes
the role of Defending
Assumption types. If you do not find gaps in the argument then this
indicates that you can expect a Defender based assumption question. For example:
People who read a
lot are more intelligent than the other people. Thus, reading must cause a
person to be intelligent
Conclusion: Reading must cause a
person to be intelligent.
So, to defend the argument, the author must have assumed
that intelligence is solely based on reading and cannot happen by other factors
such as sleeping more, regular exercise, a good diet or genetics, which, if
proved, can weaken the conclusion.
So, Defender assumptions eliminate a possible source of
attack on conclusion.
f.
This
is most critical-You need to consider all the answer choices as correct
and the stimulus is in question. Only the metal each choice carry varies.
The conclusion must pass the correct assumption test else it will fall apart.
g.
Assumption question stem contains following types of
indicating words:
·
Author assumes,
·
conclusion can’t be true unless which of the
following is also true
·
validity of the conclusion is checked by
·
argument above depends on which of the following
Steps to find the correct/incorrect assumption answers
choices:
a.
Logically negate the answer choice, which you feel is
the assumption (don’t apply this rule to all 5 choices as this will be time
consuming). If by logically negating the choice, the argument and the
conclusion falls apart (in simpler terms, if negated answer choices weakens the
conclusion), then this is your correct choice. Remember, only one option, upon
negation, can decide the validity of argument/conclusion.
b.
If an answer choice starts with “At least one” or “At
least some” then the chances are high for this option to be the correct one.
But, do not simply assume that this is the only one. Try to negate and check
the argument.
c.
Shell Game Trap. These will usually be present as
one of the option.
d.
If any answer choice mentions extreme/strong reasons
such as:
The most
Main factor/objective
Primary reason
Usually these answers fall in the incorrect choice
category.
e.
Watch out for negative indictors (not, never, no). These
can be
your Defender assumption answer choice.
f.
Cause-Effect relationship in Assumptions:
When the author mentions a certain cause-effect relation
then it is assumed that it is true. The stated cause is the only cause which
will always produce the effect. So, correct answer choice will fall into one of
the following:
g.
Eliminate an alternate
cause for the stated effect in the argument.
h.
Shows that when the cause occurs, the effect occurs.
i.
Shows when the cause does not occur, the effect does
not occur.
j.
Eliminates the reversed relationship (effect
>>> cause). This type is one of the most frequently occurring types.
k.
Shows that the data used to make the casual statement
are accurate, or eliminate possible problems with the data.
Now, let’s analyze one CR question from OG10:
48. A researcher
discovered that people who have low levels of immune-system activity tend to
score much lower on tests of mental health than do people with normal or high
immune-system activity. The researcher concluded from this experiment that the
immune system protects against mental illness as well as against physical
disease.
The researcher’s conclusion depends on which of the
following assumptions?
A. High immune-system activity protects against mental
illness better than normal immune-system activity does.
B. Mental illness is similar to physical disease in its
effects on body systems.
C. People with high immune-system activity cannot develop
mental illness.
D. Mental illness does not cause people’s immune-system
activity to decrease.
E. Psychological treatment of mental illness is not as effective
as is medical treatment.
Premise 1: A
researcher discovered that, on tests of mental health, people who have low
levels of immune-system activity tend to score much < people with normal or
high immune-system activity.
Conclusion: Immune
system protects against mental illness as well as against physical disease.
In the premises, we are given some details on mental
health tests, low levels of immune system activity, normal or high
immune-system activity and score while in the conclusion, we are given Immune
system, protection, mental illness and physical disease. We are provided with
info on MENTAL TESTS and the direct relationship b/w them:
The higher the level of immune-system activity
>>> the higher score you will get
But wait, no details on mental illness in the premises. The researcher forgot to mention
the relationship b/w immune system and mental-illness. Also, this is the catch
to decide that we will have Defender assumption.
Now, let’s break and analyze the answer choices:
A. High immune-system activity protects against mental
illness better than normal immune-system activity does. [There is no casual
relationship b/w mental illness and immune-system activity mentioned in the
conclusion. Incorrect]
B. Mental illness is similar to physical disease in its
effects on body systems. [This is a case of Shell Game fallacy. In the
conclusion statement, mental illness and physical decease are mentioned and
thus this choice is created to mislead. But, it fails to connect with mental
illness. Incorrect]
C. People with high immune-system activity cannot develop mental illness. [There is no casual
relationship b/w mental illness and immune-system activity mentioned in the
conclusion. This is adding extreme case and also, this is OPPOSITE to the conclusion. Incorrect]
D. Mental illness does not cause people’s immune-system
activity to decrease. [If mental illness doesn’t change the immune-system
activity then this is the case which author missed to defend the argument. Correct]
E. Psychological treatment of mental illness is not as
effective as is medical treatment. [This is completely out of scope new
information. No relationship b/w treatment and illness is in context of the
conclusion. Incorrect]