GMAT VARC Inference and Conclusion: Questions, Examples and Strategy

Inference and Conclusion questions can be difficult when the correct answer is not stated directly in the passage. You may need to determine what follows from a set of facts, identify an idea implied by the author, or decide which viewpoint is best supported. The challenge is to distinguish a conclusion that is logically supported from an option that adds an assumption or goes beyond the given details.

PW's GMAT study materials and practice questions can help you practise identifying relevant facts, evaluating answer choices and drawing conclusions from the evidence provided. Familiarising yourself with common question stems and practising different inference-based questions can help you approach these questions with greater accuracy.

Inference and Conclusion

Inference and Conclusion questions test your ability to understand what logically follows from a passage, even when the conclusion is not stated directly. These questions can appear in both Critical Reasoning (CR) and Reading Comprehension (RC) and may require you to identify a conclusion, determine what must be true or understand the author's likely viewpoint.

Common question stems include:

• "Which of the following can be inferred from the passage?"

• "Which of the following has been implied by the author?"

• "If the information given above is true, which of the following must also be true?"

• "Which of the following is the author most likely to agree with?"

• "Which of the following is the author least likely to agree with?"

The key is to stay within the evidence given in the passage. An answer does not need to repeat a sentence word-for-word, but it must follow logically from the given facts and relationships.

What Is an Inference?

An inference is an unstated conclusion that can be logically derived from the facts or details presented in a passage.

For example, a passage may give you several facts without directly stating the conclusion that connects them. Your task is to determine what conclusion follows from those facts without adding assumptions of your own.

Assumption vs Inference

The key difference is:

• Assumption: What must be true for the argument to work?

• Inference: What must be true based on the details given?

An inference therefore moves from the given facts towards a conclusion that those facts support.

Common Inference Question Types

1. "Can Be Inferred" Questions
A question may ask:

Which of the following can be inferred from the passage?

Look for a conclusion that is directly supported by the details provided. The correct answer should follow logically without requiring additional assumptions.

2. "Has Been Implied" Questions
A question may ask:

Which of the following has been implied by the author?

The answer does not have to be stated word-for-word. However, it must logically follow from the passage.

3. "Must Also Be True" Questions
A question may ask:

If the information given above is true, which of the following must also be true?

These questions require the strongest level of certainty. The correct answer must necessarily follow from the given facts.

4. Author Agreement Questions
In Reading Comprehension, inference questions can also ask:

• What is the author most likely to agree with?

• What is the author least likely to agree with?

To answer these questions, identify the viewpoint that is best supported by the passage.

The True-False-Can't Say Framework

A useful way to evaluate answer choices is to place each one into one of three categories.

True
The statement is supported by the details given in the passage.

False
The statement contradicts the details given in the passage.

Can't Say
The passage does not provide enough evidence to determine whether the statement is true or false.

GMAT Rule
Do not treat a "cannot be determined" statement as false.

A lack of evidence is not the same as a contradiction. If the passage does not provide enough details to establish whether a statement is true or false, the correct classification is Can't Say.

Example 1: Farming, Fertilizers and Water Pollution

Consider the following details:

• Producing high yields of the same crop year after year requires high levels of fertilizers and pesticides.

• These chemicals pollute water supplies.

• Experts recommend crop diversification and yearly crop rotation.

• Government price-support benefits require farmers to produce the same crop for several years.

Question
The statements above, if true, best support which conclusion?

Analysis
Efforts to reduce water pollution encourage farmers to diversify crops and rotate plantings.

However, government price-support benefits require farmers to produce the same crop for several years. Repeatedly growing the same crop can require greater use of fertilizers and pesticides.

Therefore, the requirements for government support can work against efforts to reduce water pollution.

Correct Inference
Government rules for supporting farm prices can work against efforts to reduce water pollution.

Eliminating the Other Options

Farming must stop
This conclusion is too extreme. The passage provides other possible solutions, including crop diversification and crop rotation.

Farmers can definitely remain profitable
The passage does not provide enough details about profitability. Therefore, this cannot be determined.

New farming techniques will be developed
This is a prediction about the future. The passage does not establish that new techniques will definitely be developed. Therefore, this cannot be determined.

Government price support is insufficient to keep farmers out of debt
The passage does not establish:

• Whether farmers are in debt

• Whether support payments are sufficient

• Whether support payments are insufficient

Therefore, this also cannot be determined.

Example 2: Budget Deficit vs Trade Deficit

Consider these details:

• A national budget deficit occurs when government expenditure exceeds revenue.

• A trade deficit concerns imports and exports.

• Countries with large budget deficits do not necessarily have large trade deficits.

• When deficit figures are adjusted for reliable comparison, there is no such correlation.

Question
Which of the following can properly be inferred?

Correct Inference
Reducing a country's national budget deficit will not necessarily result in a reduction in its trade deficit.

Why?
The passage establishes that there is no necessary relationship between budget deficits and trade deficits.

Therefore, reducing one does not necessarily result in a reduction in the other.

Important Inference Lesson
Do not reverse the direction of a relationship.

If the passage establishes:

A large budget deficit does not necessarily produce a large trade deficit.

You cannot automatically conclude:

A large trade deficit does not necessarily produce a large budget deficit.

The reverse relationship has not been established.

Example 3: Taxpayers and Registered Voters

Consider the following details:

• Ten years ago, the number of taxpayers was slightly greater than the number of registered voters.

• The number of taxpayers has doubled.

• The number of registered voters has increased, but at a lower rate.

Let:

T = taxpayers
V = registered voters

Initially:

T > V

Taxpayers have grown faster than registered voters. Therefore, the ratio:

V/T

must have decreased.

Correct Inference
The proportion of registered voters to taxpayers has decreased over the last 10 years.

Why Other Options Fail

"Taxpayers are now fewer than registered voters"
This is contradicted by the fact that taxpayers started slightly higher and grew faster.

"Every registered voter is also a taxpayer"
The given details provide totals, not the overlap between the two groups.

"The proportion remained unchanged"
This cannot be true because the two groups grew at different rates.

Key Lesson
Be careful when a question involves:

• Ratios

• Growth rates

• Proportions

• Relative changes

Different growth rates can change the relationship between two groups even when their exact numbers are not given.

Example 4: Pesticides

Consider the following details:

Massive and sustained pesticide use creates two major problems:

• It can kill the pests' natural enemies.

• It can lead to insecticide-resistant pests.

Question
How could the effectiveness of sustained pesticide use be extended?

Correct Inference
Periodically switching the type of insecticide used.

Reasoning
Some pests survive a particular insecticide. Those surviving pests may be resistant to that insecticide, reproduce and pass on the resistance.

Switching insecticides can reduce the advantage of pests that are resistant to one particular chemical.

Therefore, periodically changing the insecticide addresses one of the problems associated with sustained pesticide use.

Example 5: Tulu Plant

Consider the following details:

• Tulu plants are ornamental plants.

• They do not reproduce naturally.

• Specialized horticultural companies breed and sell them.

• The plants can be affected by fungal rot.

• Plants younger than 30 weeks generally cannot be reliably tested.

• Many plants are sold before 24 weeks.

Government Plan
The government plans to require all Tulu plants to be tested before sale.

Problem
Testing young plants may not reliably detect fungal rot.

Question
Which government action could overcome this problem?

Strongest Answer
Do not sell Tulu plants before they reach 30 weeks of age.

Why?
At 30 weeks:

• Fungal infection can be reliably detected.

• The limitation of testing younger plants is removed.

• The solution does not depend on uncertain future research.

Why Research Alone Is Weaker
Researching a new testing method may eventually solve the problem, but success is not guaranteed.

Therefore, when the question asks what could logically be expected to overcome the problem, a solution that directly removes the testing limitation is stronger.

Inference Question-Solving Strategy

Step 1: Read the Question Stem First
Identify whether the question asks for:

• An inference

• A necessary conclusion

• Author agreement

• A conclusion best supported by the evidence

Understanding the question stem helps you determine exactly what you need to establish.

Step 2: Identify the Relevant Facts
Do not try to memorise the entire passage. Focus on:

• Facts

• Relationships

• Comparisons

• Cause-and-effect statements

• Quantities

• Changes over time

• Author viewpoints

Step 3: Build the Logical Connection
Ask yourself:

"What conclusion must or reasonably can follow from these facts?"

The answer should be based on the relationship between the given details rather than an assumption that is not established in the passage.

Step 4: Test Every Answer Choice
Classify each answer choice as:

This helps you distinguish between an answer that is actually contradicted and one that simply cannot be established from the passage.

Step 5: Eliminate Unsupported Claims
Remove answer choices that:

• Introduce new information

• Make assumptions not stated in the passage

• Go beyond the evidence

• Reverse a relationship

• Make an extreme claim

The correct inference should remain within the limits of what the passage establishes.

GMAT Inference and Conclusion questions require careful attention to the facts, relationships and viewpoints presented in a passage. The correct answer may not be stated directly, but it must be supported by the evidence without introducing assumptions or going beyond what the passage establishes.

To improve your accuracy, focus on the question stem, identify the relevant details and evaluate each option against the passage. PW’s GMAT study materials and practice questions can give you opportunities to apply these strategies and build confidence in solving inference-based questions.