Analogy in Logical Reasoning

Analogy is a vital subject in reasoning. Analogy related questions are part of many types of competitive exams. So if we understand the concept of analogy, we can solve any question of this type.

The word analogy is the Latin to a Greek word that comes from the word “Analogous”. The meaning of the analogy is “proportionate”.

It determines the association between various things, incidents, elements, places etc.

 It plays an essential role in solving any problem, making decisions, creativity, memory, explanation, and communication.

We must understand the words in their general form and choose the option according to the similarities.

In any competitive exam, we will find questions of this type: three words or numbers are given, and we have to find a fourth word or number. So, first of all, we have to understand the relation between the first and second terms and then choose the correct answer based on only this relationship mentioned between the first and second terms. We will understand them with lots of examples.

Categories of Analogy:

Firstly, we have to categorise analogy to better learn the relationship between the first and second terms and easily solve the problem at first glance. The categories are mentioned below-

1. Numeric Analogy: This type of analogy is based on numbers. Look at the examples-

729:27::1681:?

In this example, if we analyse the first two terms, which are 729 and 27, then we can see that the square of 27 is equal to 729; then the relation between the first term and second term is that the first term is the square of the second term. So this relationship we have to form between the third and fourth term, so 1681 is the square of 41; so the missing term will be 41

729:27::1681:41

We will try to understand it with the second example-

231:573::341:?

If we deeply see the first term, then the first term two 231 has a relation with the second term in this form

2*2+1=5

3*2+1=7

1*2+1=3

So we have to establish this relationship with the third term

3*2+1=7

4*2+1=9

1*2+1=3

So the fourth term will be 793

231:573::341:793

2. Alphabetic analogy: this type of analogy contains alphabetical letters. Look at the first example-

B:Y::C:?

In this example, we can see that the letter B is the second letter of the alphabetic series, and the letter Y is the second last letter of the alphabetic series. C is the third letter of the alphabetic series, and X is the third last letter of the alphabetic series, so the missing number will be X.

B:Y::C:X

Example 2-

AI:BJ::CK:?

In this example, all the terms consist of two alphabetic letters, so if we see only the first letter of all the terms, we find that they are in a series that is A, B, and C, so the fourth term’s first letter will be D. Now look at the second letter of all the terms. We observe that they are also in a sequence of alphabetical series, that is, I, J, K, so the second letter of the fourth term will be L. And the missing term is DL.

AI:BJ::CK:DL

3. Numeric-Alphabetic Merging Analogy- This type of analogy contains numbers as well as alphabetic letters. We can understand it by this example-

B:16::D:?

So we will try to form a relationship between the first and second terms, that is, B and 16; as we can see, B is the second letter of the alphabetic series. 

2*2*2*2=16

Now D is the fourth letter of the alphabetic series

4*4*4*4=256

B:16::D:256

Example 2-

MAN:28::RAM:?

As we can see, the first term is MAN, M is the 13th letter of the alphabetic series, A is the 1st letter, N is the 14th letter of the alphabetic series, and if we take their sum, that is 13 + 1 + 14 = 28 we get the second term. Now in the third term, R is the 18th letter of the alphabetic series, A is the 1st letter of the alphabetic series, and M is the 13th letter of the alphabetic series, and their Ottawa Spain Madrid Sum will be 18+1+13=32, that is the missing term.

MAN:28::RAM:32

4. General Science-Based Analogy: This type of analogy is based on general Science. Look at this example-

Silver:Solid::Petroleum:?

We know that silver remains in the solid state at room temperature, and petroleum remains in a liquid state.

Silver:Solid:: Petroleum: Liquid

Example 2-

Length:Metre:: Force:?

As we can see that the SI unit of length is Metre, so the SI unit of Force will be derived from the missing term Newton.

Length:Metre::Force:Newton

5. General knowledge Based Analogy: This type of analogy is based on general knowledge. Look at this example-

Blackboard:Chalk::Paper:?

We can write on a blackboard with the help of chalk, just like we can write on paper with the help of ink. So the missing number will be ink.

Blackboard:Chalk:: Paper:Ink

Example 2-

 Canada:Ottawa::Spain:?

As per our concern, Ottawa is the capital of Canada, so the missing term will be the capital of Spain, and that is Madrid.

Canada: Ottawa:: Spain: Madrid

6. Grammar Related Analogy: this type of analogy is based on grammar-related questions. Look at this example-

Honest:Dishonest::ugly:?

Dishonest is the opposite word of the word honest, so the missing term will be the opposite word of the ugly, which is beautiful.

Honest: Dishonest:: ugly: beautiful

Example 2-

Cattle:Herd::Flower:?

As per our concern, hard is the collective form of capital; therefore, the missing term will be the collective form of a flower, which is a bouquet.

Cattle:Herd::Flower:Bouquet

From the above examples, we can find steps for the analogy type questions. They are-

Step 1# Firstly, we have to compare the first and second terms. Find the relation between them.

Step 2# The relation between them will be based on the category of analogy.

Step 3# After this, we will try to get the answer only about the relationship mentioned between the first and second terms.

Conclusion:

 After the detailed study of analogy in logical reasoning, now we understand that analogy is the concept in which a relation is formed between assorted types of incidents, places, elements, things, numbers, and alphabetical letters.

We tried to form the types of analogy so that we could easily solve the questions at first glance. Some questions can also be image type. We will try to analyse the image and which type of analogy it is.

  The analogy is a way to convince someone to change their mind about a particular issue. It can conclude a new case. Studying analogies also makes our communication skills better.