Coding and Decoding is a topic that is part of the reasoning ability syllabus. As the name suggests, candidates have to decode a code given in the question and answer the related questions accordingly. It is one of the most common topics from which questions are asked in competitive exams be it SBI PO, SBI Clerk, IBPS PO, IBPS Clerk, and other examinations. These questions are posed to judge a candidate’s ability to decipher patterns or rules that are used when devising codes. You can easily expect 1 to 2 questions from this topic in any banking/SSC/Railways exams. Hence, a good grip over this topic will be advantageous for you. Let’s understand this topic in detail below.
Coding is a method to encrypt words and numbers following one pattern or another. Decoding is the method of deciphering the pattern and subsequently finding the hidden meaning. In this chapter, we will learn about the various methods of coding that are assessed in competitive examinations and how we can decode them simply.
Alphabet-to-Alphabet Coding
This method is also known as Letter-Letter coding wherein letters of the code are encrypted in code using other alphabets that follow a certain pattern. Here, there is no use of numbers. This Letter-Letter coding may follow more than 1 pattern which is why candidates must know the letters of the English alphabet both from the A to Z and vice-versa.
For example;
If KOLKATA is written as LPMLBUB then which of the following reads HYDERABAD?
The correct answer is option (b).
Explanation: The coding pattern follows that code is encrypted by using the next alphabet that follows the correct spelling. i.e. H was replaced with I, Y with Z and so on.
2) In a certain coded language PUBLIC is coded as OVAIJA and POWERS is coded as OPUFOO, then what is the code of SYSTEM?
Ans. b;
PUBLIC – OVAIJA
POWERS –OPUFOO
Then, SYSTEM – OUOOFI
Every vowel is coded as the next consonant and every consonant is coded as the previous vowel.
3) If ‘HIGHFLOW’ is coded as ‘GFHGXPMG’ then how will ‘FLIPKART’ be coded?
Ans: b
Number Coding
As the name suggests, here alphabets are coded with the help of numbers that follow a certain pattern.
If Delhi is written as 38, how is New York written?
The correct answer is option (c)
Explanation: D=4, E=5, L=12, H=8, 1=9= 38. Similarly, find the corresponding numbers to the alphabets in the word New York to get 111.
Mixed Coding
Here, a combination of numbers and alphabets are used to form a code. Several types of patterns may emerge from the combination of the two. Let us look at some examples for more clarity.
If the letters of the word ‘CYBERTRONIANS are arranged in increasing order of their numerical value, then which letter would be placed last?
Explanation: The correct answer is option (d). The letter Y has the highest numerical value (25) and will thus be placed last.
If cat=9, simple=36 and abandonment=121, then president=?
Explanation: The correct answer is (c). The numerical value of the words has been derived by squaring the number of alphabets present in the word. Since “president” is a 7-letter word, its numerical value will be the square of 7, i.e., 49.
Directions (26-30): Study the information and answer the following questions:
In a certain code language,
" digital era even world" is coded as " Q1 H1 D5 K4 "
" seems unique about adhaar " is coded as " U5 L65 X1 V1 "
" draw supplies food medicine" is coded as "H1 E5 K4 U3 "
Now answer the following:
What is the code for ‘magnet’ in the given code language?
Ans: c
Numerical value of that letter in a word which comes first according to English dictionary – A - 1
Immediate preceding of reverse of second letter in word – A - Y
What is the code for ‘recruitment’ in the given code language?
Ans: b
Numerical value of that letter in a word which comes first according to English dictionary – C – 3
Immediate preceding of reverse of second letter in word – E – U
What is the code for ‘signboard’ in the given code language?
Ans: c
Numerical value of that letter in a word which comes first according to English dictionary – A – 1
Immediate preceding of reverse of second letter in word – I – Q
What is the code for ‘students’ in the given code language?
Ans: a
Numerical value of that letter in a word which comes first according to English dictionary – D – 4
Immediate preceding of reverse of second letter in word – T – F
What is the code for ‘green’ in the given code language?
Ans: d
Numerical value of that letter in a word which comes first according to English dictionary – E – 5
Immediate preceding of reverse of second letter in word – R – H
Symbol Coding
In this type of coding, symbols are used to form a code. These symbols may be used together with numbers, alphabets, neither, or both.
If January= @, October= #, August= & and December= %, then which of the following represents the Gandhi Jayanti in India?
The correct answer is (b). Gandhi Jayanti is celebrated on October 2nd. This question also requires that candidates have a sound knowledge of general awareness.
Miscellaneous Coding
Here, a combination of numbers, alphabets and symbols are used where a set pattern is described in the question. Here, this question is exclusive to the question and may not be applied otherwise outside of the same. Sometimes elaborate codes may be presented from which a series of questions are asked.
For example;
Study the following information carefully and answer the questions given below:
In certain code language,
‘computers with better and’ is coded as ‘ pl ob yw qa’,
‘speedy better and efficiency’ is coded as ‘cs qa bn ob’,
can accomplish argument computers’ is coded as ‘ pl lk pa mw’ and
‘accomplish holds while efficiency’ is coded as ‘bn lk fd In’. (All the codes are two- letter codes only.)
Solution:
better/and – ob/qa
computers – pl
with – yw
efficiency – bn
speedy – cs
accomplish – lk
can/argument – pa /mw
holds /while – fd/in
Now answer the questions from i-v.
i. What does the code ‘bn’ stand for in the given code language?
Ans: c
ii. Which of the following accomplish be the code for ‘what holds while’ in the given code language?
Ans: b
iii. What is the code for ‘can’ in the given code language?
Ans: d
iv. What does the code ‘cs yw pl’ stand for in the given language?
Ans: c
v. What does the code ‘efficiency’ stand for in the given code language?
Ans: c
2. Consider the following;
“David eats cake” is 544;
“Broken piece of the coffee mug” is 65#363; and
“500 seconds of accuracy” is 37#8, then what is the code for the following?
i. “Girls are playing soccer”
ii. “the quiet of the night”
iii. “champion wrestler from Abyssinia”
Explanation: For question no (i), the correct answer is (a) because simply the number of alphabets in each word has been used to substitute the words.
Question (ii) option (c) is correct where the same rule from above has been utilized with the word “of” being replaced with #.
For question 3, the same rule from question (i) has been re-applied. If a word has more than 10 alphabets, then the two numbers forming the number of alphabets are added to obtain a single-digit number. For example, “abbreviation” has 12 letters in it. So, 1+2=3. If required, the word “abbreviation” will be coded as 3.
Coding and Decoding is an important chapter for most government examinations. Questions from this subject are assessed one way or another and you can expect 3-5 questions from Coding and Decoding.