Deduction vs Inference – LNAT Question Types Explained

What is the difference between ‘Deduction’ and ‘Inference’?

Deduction

‘Deduction’ is a process of reasoning in which a conclusion is drawn logically and necessarily from given premises. It is a method of reasoning that moves from general premises to a specific conclusion.

Examples of Deduction

• All humans are mortal. Socrates is a human. Therefore, Socrates is mortal.
• All dogs are mammals. A Labrador is a dog. Therefore, a Labrador is a mammal.
• If it rains, the ground will be wet. It is raining. Therefore, the ground is wet.
• All triangles have three sides. A scalene triangle is a type of triangle. Therefore, a scalene triangle has three sides.
• If someone studies regularly, they will perform well in exams. Jane studies regularly. Therefore, Jane will perform well in exams.

Inference

‘Inference’ is a process of reasoning that involves drawing a conclusion based on evidence and reasoning, usually moving from specific observations to broader generalizations.

Examples of Inference

• The grass is wet. It may have rained earlier.
• John is wearing a heavy coat and gloves. It is probably cold outside.
• The bakery has a long line. The bakery might have a special promotion today.
• A student is yawning and rubbing their eyes during a lecture. The student is likely tired.
• Sarah is carrying an umbrella and is wearing rain boots. The weather forecast probably predicted rain.

To differentiate between ‘deduction’ and ‘inference’, remember that deduction relies on strict logical relationships between premises and conclusions, while inference is based on evidence and reasoning. Deduction typically moves from general to specific, whereas inference moves from specific to general.

How to answer Deduction and Inference questions in the LNAT?

• Read the question carefully to understand whether it is asking for a deduction or an inference.
• Identify the keywords in the question and the passage to help you determine the type of question.
• Focus on the specific details in the passage to make accurate inferences.
• Use the process of elimination to remove incorrect answer choices.
• Be mindful of extreme answer choices or absolutes in deduction questions.
• Look for patterns or relationships between ideas in the passage to help with inference questions.
• Take notes or underline important information in the passage to help with your reasoning.
• Re-read relevant parts of the passage if necessary to ensure your understanding.
• Be cautious of your assumptions and ensure they are based on the information provided.
• Manage your time effectively by allocating a set amount of time per question and moving on if you are stuck.

Remember ! Questions in the LNAT may not always have the keywords ‘Deduction’ or ‘Inference’. Read the question carefully to understand the intention – what does the question want you to do?

Examples of ‘Deduction’ questions.

a. If all apples are fruits and some fruits are green, which of the following must be true?
All apples are green.
Some apples are green.
No apples are green.

b. If no cats are friendly and some friendly animals are dogs, which of the following must be true?
All dogs are friendly.
No dogs are friendly.
Some dogs are friendly.

c. If all vehicles require fuel and bicycles do not require fuel, which of the following must be true?
Bicycles are vehicles.
Bicycles are not vehicles.
Vehicles do not require fuel.

d. If all politicians are dishonest and some dishonest people are wealthy, which of the following must be true?
All politicians are wealthy.
Some politicians are wealthy.
No politicians are wealthy.

e. If all flowers have petals and some petals are white, which of the following must be true?
All flowers are white.
Some flowers are white.
No flowers are white.

Keywords to identify and answer ‘Deduction’ related questions in the LNAT.

• must be true
• necessarily
• logically follows
• if…then
• all, no, some

Examples of ‘Inference’ questions.

a. Mary is wearing a swimsuit and carrying a beach towel. Which of the following can be inferred?
Mary is going to the pool.
Mary is going to the beach.
Mary is going swimming.

b. A store has empty shelves and a “50% off” sign. Which of the following can be inferred?
The store is closing down.
The store is having a sale.
The store is out of stock.

c. Tom is wearing a suit and tie and carrying a briefcase. Which of the following can be inferred?
Tom is going to a wedding.
Tom is going to a business meeting.
Tom is going to a job interview.

d. It is a sunny day and children are playing in the park. Which of the following can be inferred?
The children are on a school trip.
The weather is warm.
The park is near a school.

e. Jane is carrying a violin case and sheet music. Which of the following can be inferred?
Jane is going to a violin lesson.
Jane is going to a music store.
Jane is going to a concert.

Keywords to identify and answer ‘Inference’ related questions in the LNAT.

• can be inferred
• most likely
• probably
• based on the information
• suggests