A. Critical Reasoning Introduction

Critical Reasoning section of GMAT tests your reasoning ability but it is of a much higher level than the ordinary Logical Reasoning. A type of reasoning that a management graduate is required to follow in an amazing variety of work situations.

The tests are similar to Reading Comprehension to the extent that a passage is to be read and questions answered with respect to the information in the passage. The difference is that these passages rarely exceed 100 words and contain information that is to be understood clearly. Reading comprehension passages are long and punctuated with peripheral facts. By contrast, Critical Reasoning passages are quite short, and every single word should be considered very carefully; there are subtle shades of meanings, which often require a reading between the lines.

The key to solving these types of questions is to recognize the premise and the conclusion. Essentially, two or more premises lead to a conclusion and assumptions are the unstated premise in this chain.

However, life at GMAT is not absolutely black and white. This rule is to be applied in a variety of ways, some of the questions require you to understand the question and apply the rule in a highly subtle and skilled manner.

The good news is that the questions are based on elementary rules of logic and good old common sense. ETS says that – ‘no knowledge of terminology and of the conventions of formal logic is presupposed.’

The instructions at the beginning of the test are:

DIRECTIONS: After reading the question, pick the best answer among the choice that follow.

B. Basic Terminology

Before we actually tackle Critical-reasoning questions it would be a good idea to familiarize ourselves with the basic terminology.

Example 1:
David was talking during class, so he didn’t understand the teacher’s instructions.

Here, the conclusion is that David did not understand the teacher’s instructions.

The Premise that led to the conclusion is that David was talking.

Thus,

A Premise is a statement that serves as the basis of an argument. There may be more than one premise in a Critical Reasoning passage. All these premises put together lead to the conclusion.

A Conclusion is the point that the author is trying to convince the readers about with the help of the premises in the passage.

Arguments contain a number of premises and possibly more than one conclusion. Hence, it becomes necessary to classify and connect things and events in order to analyze the argument.

An Assumption is also a premise but an unstated one. It is a line of thought based on which the author makes a conclusion. The author’s conclusion is always dependent on an assumption.

An Inference is something that is implied in the passage yet not directly stated. It is different from an assumption because unlike the assumption the inference does not directly affect the conclusion. In other words the conclusion does not depend upon the inference. There can be more than one inference in a critical reasoning passage.

C. Types of Critical Reasoning Questions

1. Conclusion based questions:
2. Assumption type of questions:
3. Strengthen/ Weaken the argument type of questions:
4. Inferential type of questions:
5. Similar reasoning type of questions:

Most critical reasoning passages are in the form of arguments in which the writer tries to convince the reader of something.

There are three main parts to an argument.

The conclusion: this what the author is trying to convince us of.
The premise: these are the pieces of evidence that the author gives to support the conclusion.

An assumption: is also an evidence (but it is unstated) without which the entire conclusion becomes invalid.

In evaluating an argument, the first step is to identify the components – the premise and the conclusion.

The parts of an argument can be identified by certain cue words.
A premise may be recognized by words such as ‘if’, ‘given that’, ‘since’, ‘because’, ‘for’, ‘suppose’, and ‘in view of’. They signal the presentation of evidence and reasons in support of a fact or a claim.

Conclusions, on the other hand, may be preceded by words like ‘thus’, ‘hence’, ‘so’, ‘indicates that’ and ‘therefore’. Without cue words, identifying and analyzing an argument becomes difficult. Look for a statement that cannot stand alone, i.e. a statement that needs to be supported by premises.

If you cannot find the conclusion look for the premise instead. These are the parts of the arguments that support the conclusion. Lets us see an example where the premises have been stated and a conclusion is to be provided.

An assumption is also a premise but it is an unstated one. It is a line of thought based on which the author makes a conclusion. The author’s conclusion is always dependent on an assumption.

The Critical reasoning question consists of a short passage followed by questions like –

“Which of the following best serves as an assumption that would make the argument above logically correct?” Read the question before you read the passage, so that you know that without the assumption plugged in, the conclusion will not hold.

If you decide to read the passage first, it may appear to be perfectly reasonable. It is only when you read the question that you realize that you have missed something or that there is a flaw in the reasoning. You will therefore have to go back to the passage. To avoid such a waste of time it is advisable that you read the question first.

Example
In order to save money in this fiscal year, the management voted to cut the overtime hours and hence freeze overtime wages. The shortsighted example is yet another example of the management being penny wise and pound-foolish. The production that will result from this action will cause many quality defects, resulting in market complaint. This will ultimately result in loss of market share and revenues.

Which of the assumptions does the author make in order for this argument to be logically correct?

(A) The workers are already overpaid and so the overtime pay freeze is warranted.
(B) The management cares less about the quality of the product than it does about saving money.
(C) If they do not work overtime and receive overtime pay, the workers will become lax in producing quality products.
(D) The management does not feel that less wages will necessarily result in quality taking a beating.
(E) The loss in revenue will not be as much as the money saved by cutting overtime wages. 

The passage attempts to justify that the company will eventually have to lose much more than it is trying to save. Alerted to the fact that the logic is faulty (by having first read the question) you probably picked up the subtle shift from ‘freeze overtime pay’ to ‘cause many quality defects’. If you did, you might have asked yourself, ‘the fact that the salary of the workers are being cut does not necessarily mean that they will produce poor quality goods’. Thus there is a gap in the logic. To justify the conclusion presented, we need to assume that cutting wages will result in poor quality. This said in option (C).

Strengthen and Weaken the Argument

The questions that follow the passage are of the type:

• Which of the following, if true, would most support the views/conclusion/statement?

• Which of the following statements, if true, most weaken/strengthen the author’s claim that...

• Which of the following, if true, would negate/strengthen the author’s point of view?

If a question asks you to strengthen an argument, it is asking you to find a hole in the argument and to fix it with additional information. The argument may not be complete by itself and the answer looks more like a premise or an assumption.

The correct answer will strengthen/weaken the argument with new information. If you see an answer choice that is straight from the passage, its wrong. The answer choice will support the conclusion of the passage if it is a strengthen the argument type of question. Find the conclusion in the passage, then try out each answer choice to see whether it makes the conclusion stronger.

Like assumption questions and strengthen-the-argument questions, weaken-the-argument questions frequently point out the gaps inherent in inductive reasoning. You don’t need to fix the hole in the argument but expose it.

There are two main types of reasoning: Deductive and inductive. In deductive logic the conclusion must follow from the premises. In inductive logic the conclusion may be true, but it does not have to be. Three popular kinds of inductive logic are:

1. Statistical arguments where the statistics are representative.
2. Arguments by analogy where the two situations are analogous; and
3. Causal argument – where there might be an alternative cause.

These three kinds of inductive logic are very important in assumption questions, weaken-the- argument questions and strengthen-the-argument questions.

Example
Production houses like Columbia Pictures, Twentieth Century Fox etc. provide stock options to their employees. These companies are employing the highest number of people in the industry. There is little reason why most production houses cannot provide the same benefits to their employees.

Which of the following if true would weaken the arguments?

(A) Stock options is not offered to all the employees of a company.
(B) Columbia Pictures and Twentieth Century Fox have fewer members on their board.
(C) Most other production houses do not have the tax benefits that Columbia & Twentieth Century Fox have because they are the biggest employers in the industry.
(D) Other production houses have much more business.
(E) The trend to offer stock options in the industry has not caught on yet.

The answer is (C). If (C) is true; it explains why the other companies have not provided the benefits. (A) Does not weaken the arguments. It is secondary that the benefits are not extended to everybody. If (D) is true then it only strengthens the argument. (E) Is an observation but not as valid as (C).

Exercises

1. The Starship Enterprise is in danger of imploding from laser beams if the warp generators are not toroid resistant. Captain Spock says that no malleable circuits are toroid resistant and all warp generators are made of malleable circuits.

What is the conclusion that can be drawn from Captain Spock’s reasoning?

(A) Laser beams do not affect the malleable circuits.
(B) The Starship Enterprise is not in danger.
(C) The Starship Enterprise will implode from laser beams.
(D) Warp generators are toroid resistant.
(E) None of the above.

The correct answer is (C).
The trick is in the way the passage is worded. Warp generators are made of malleable circuits and malleable circuits are not toroid resistant. If they are not toroid resistant they are in danger of imploding from laser beams. This a typical critical reasoning question that can also be solved with the help of a Venn diagram. The passage requires clear understanding of the language, the logic is very simple. 

2. You are visiting your cousin Tony. Tony begins by telling you what a great job he has. ‘I am a future millionaire,’ he says. ‘All the top executives in the company are millionaires and I am a future top executive.’ Tony is already planning on what kind of a mansion he wants to build. 

What is the assumption that Tony is making?

(A) All millionaires have mansions.
(B) Top executives become millionaires.
(C) He works for a company where all the top executives become millionaires.
(D) Tony thinks he has a great job.
(E) None of the above.

The assumption is clearly (C). (B) Talks about top executives and not all the top executives and hence is not the answer.

3. South American girls have won the Miss World contest at least for the last 4 years in a row. Therefore the winner this year will also be a South American.

Which of the following definitely strengthens the conclusion?

(A) The Miss World contest was started 15 years ago and different countries have won it in the past.
(B) There are more participants from South America this year than before.
(C) More than 50% of the judges are from South America.
(D) A different country has won the contest every year in the last decade.
(E) It has been noticed that the winners of the contest rotate through different continents in a 5-year cycle. The winner five years ago was an Asian country.

The correct answer is (E).
(B) And (E) qualify as the options that strengthen the conclusion. However, (E) definitely strengthens the conclusion that the winner this year will also be a South American because the option says that a continent has a winner for 5 years in a row. (A) and (D) weaken the argument.

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