# CSAT Study Notes: Basics of Coding-Decoding

By Ashutosh Yadav|Updated : January 10th, 2021

Hello Students,

In this article, we will cover the Coding-Decoding section of the reasoning Syllabus for the competitive Examinations. These notes will help you get a basic understanding of the topic.

Hello Aspirants,

Coding-decoding is one of the most widely asked topics in Reasoning Section. Initially there used to be different type of questions that were asked in Exam while now-a-days as the level of Exams is increasing, new type of questions are added in the topic to make the overall paper challenging.

So in this article, we are going to discuss basics related to coding-decoding and each type of questions from this topic so that it will be easy for you to understand the approach to solve those questions.

Let’s see various types of questions from coding-decoding one by one.

Type I: Sometimes the alphabets are replaced by some other alphabets in a given word and thus a coded word is obtained. The alphabets replacement occurs according to some pattern. We have to observe that pattern and implement the same in the question asked.

Q-1. In a certain coding language, ‘WISDOM’ is written as ‘OMFQKU’ then how will ‘WATER’ be written in that language?

Solution:

After proper observation, we can see that:

W-2=U

I+2=K

S-2=Q

D+2=F

O-2=M

M+2=O

And now the coded alphabets are written in reverse order.i.e. OMFQKU

Same pattern will be used for finding the code for WATER

W-2=U

A+2=C

T-2=R

E+2=G

R-2=P

And now the coded alphabets are written in reverse order.i.e. PGRCU. So this is the coded word for WATER.

Type II: Sometimes the alphabets in the word are directly replaced by some numbers or symbols. Generally more than one example of such conversion is given which helps us in identifying the coded number/symbol sequence for the asked question.

Q-2. If ‘APPLE’ is coded as 14489 and ‘BANANA’ is coded as 315151 THEN how will ‘PALE’ be coded?

1. 1489
2. 1589
3. 5189
4. 4189
5. None of these

Solution:

In the given question, code for APPLE and BANANA are given which enables us to get the code for each of the alphabet for word ‘PALE’.

Note: We can find code for any word consisting alphabets A,P,L,N,B,E.

A-1

P-4

L-8

E-9

B-3

N-5

Then ‘PALE’ will be coded as

P-4

A-1

L-8

E-9

Type III: Sometimes the coding is not at alphabetical level while it is given directly for the words.i.e. one word is replaced by some other word. So we have to be careful while giving the answer because we have to write the coded word as the answer for the one which is logically the answer.

Q-3. If ‘RED’ is called ‘WHITE’, ‘WHITE’ is called ‘BLUE’, ‘BLUE’ is called ‘GREEN’ and ‘GREEN’ is called ‘BLACK’, then what will be the colour of blood?

1. RED
2. WHITE
3. GREEN
4. BLUE
5. BLACK

Solution:

In this example, logically the color of blood should be RED but we have to write the coded word for the word RED which is WHITE. So WHITE is the answer for this question.

Type IV: (In trend) In some of the questions, three or four complete messages are given in the coded language and the code for a particular word is asked. To analyse such codes, any two messages bearing one or more common words are picked up so that we can extract the coded words for the actual words. Proceeding similarly by picking up all possible combinations of two, the entire message can be analysed and all the words can be decoded.

Directions: In a certain coded language:

1. ‘money is not everything’ is written as ‘ma pa na ra’,
2. ‘everything is important’ is written as ‘na ma ta’,
3. ‘something is not right’ is written as ‘pa na ga sa’

Solution:

From first two statements, we can infer that ‘everything is’ is written as ‘ma na’

From first and third statements, we can infer that ‘is not’ is written as ‘pa na’

From these two conclusions, we can infer that

‘is’ is written as ‘na’

‘everything’ is written as ‘ma’

‘not’ is written as ‘pa’

Now we can look at first statement and infer that

‘money’ is written as ‘ra’

Now we can look at second statement and infer that

‘important’ is written as ‘ta’

‘Something right’ is written as ‘ga sa’

Q-4. What is the code for ‘important’ in the given coded language?

1. na
2. ma
3. ta
4. ra
5. None of these

Solution:

The answer for this question will be ‘ta’.

Q-5. What is the code for ‘not’ in the given coded language?

1. na
2. sa
3. ga
4. pa
5. None of these

Solution:

The answer for this question will be ‘pa’.

Q-6. What may be the possible code for ‘something is everything’?

1. ga na sa
2. ga pa sa
3. ga ma pa
4. sa ma na
5. None of these

Solution:

‘is’ is written as ‘na’

‘everything’ is written as ‘ma’

‘something’ is written as either ‘ga’or ‘sa’

So code for ‘something is everything’ can be either ‘na ma ga’ or ‘na ma sa’.

So option 4 is correct answer.

Type V: Sometimes the code for various digits is given in a tabular form followed by some rules. The questions consist of a series of the digits (from the table) and the rules specify the modification in the digits while writing the code for the series given. We have to check all the rules while writing the code for the given series of digits.

Directions: In these questions a group of digits is given followed by four combinations of letters and symbols numbered (1), (2), (3) and (4).

Digits are to be coded as per the scheme and conditions given below. You have to find out which of the four combinations correctly represents the group of digits. Serial number of that combination is your answer. If none of the combinations is correct, your answer is (5) i.e., ‘None of these'.

Rules:

(i) If first digit is odd and the last digit is even their codes are to be interchanged.

(ii) If the first as well as the last digit is even both are to be coded as *

(iii) If the first digit is even and the last digit is odd both are to be coded as the code for last digit.

Q-7. what will be the code for ‘471536’?

1. *@\$H%*
2. R@\$H%U
3. U@\$H%U
4. R@\$H%R
5. None of these

Solution: The first as well as last digit in ‘471536’ is even so condition (ii) follows which specifies that we will have to * as a code for both 4 and 6 while the code for other digits will be as per the given table.

So option 1 is correct answer.

Q-8. what will be the code for ‘697845’?

1. U#@ARU
2. U#@ARH
3. H#@ARH
4. R#@ARU
5. None of these

Solution: The first digit in ‘697845’ is even while the last digit is odd so condition (iii) follows which specifies that we will have to code both 6 and 5 as per the code of 5 using table while the code for other digits will be as per the given table.

So option 3 is correct answer.

Q-9. what will be the code for ‘590247’?

1. @#FTRH
2. H#FTR@
3. H#FTRH
4. @#FTR@
5. None of these

Solution: The first as well last digit in ‘590247’ is odd so no condition follows which means that the code for all the digits will be as per the given table.

So option 2 is correct answer.