Coding Decoding Reasoning Material for All Competetive Exams | PDF Download
A code is a system of signals. Therefore, coding is a method of transmitting messages between the sender and receiver without a third person understanding it.The Coding and Decoding test is set up to judge the candidate’s ability to decipher the law that codes a particular message and break the code to reveal the message. Following Table will help you code-decode
A particular letter stands for another letter in letter coding.
Example – If COURSE is coded as FRXUVH, how is RACE coded in that code?
(1) HFDU (2) UCFH (3) UDFH (4) UDHF (5) UDFG
In the given code, each letter is moved three steps forward than the corresponding letter in the word. So R is coded as U, A as D, C as F, E as H. Hence (3) is the answer.
In these questions, either numerical code values are assigned to a word or alphabetical code values are assigned to numbers. The candidate is required to analyse the code as per directions.
Case I: When numerical values are assigned to words.
Example : If in a certain code ROPE is coded as 6821, CHAIR is coded as 73456 what will be the code for CRAPE?
(1) 73456 (2) 76421 (3) 77246 (4) 77123 (5) None of these Clearly, in the given code, the alphabets are coded as follows.
So CRAPE is coded as 76421, So the answer is (2)
Case II: When alphabetical code values are assigned to the numbers.
Example: In a certain code 3456 is coded as ROPE. 15546 is coded as APPLE. Then how is 54613 coded?
(1) RPPEO (2) ROPEA (3) POEAR (4) PAREO (5) None of these
Clearly in the given figures, the numbers are coded as follows.
So 54613 is coded as POEAR. The answer is (3)
In this type of question, 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 the common word are picked up. The common code word will mean that word. Proceeding similarly by picking up all possible combinations of two messages the entire message can be analysed.
Example : If tee see pee means drink fruit juice, see kee lee means juice is sweet, and lee ree mee means he is intelligent, which word in that language means sweet?
(1) see (2) kee (3) lee (4) pee (5) tee
In the first and the second statements the common word is juice and the common code word is see. So see means juice. In the second and the third statements, the common word is ‘is’ and the common code is lee. So lee means is. Thus in the second statement, the remaining word sweet is coded as kee. Hence the answer is (2).
Mixed Number Coding
In this type of questions, three or four complete messages are given in the coded language and the code number for a particular word is asked.
Example: If in a certain code language, 851 means good sweet fruit; 783 means good red rose and 341 means rose and fruit which of the following digits stands for sweet in that language?
(1) 8 (2) 5 (3) 1 (4) 3 (5) None of these
In the first and the second statements, the common code digit is 8 and the common word is good. So 8 stands for good. In the first and the third statements, the common code digit is 1 and the common word is fruit. So 1 stands for fruit. Therefore in the first statement, 5 stands for sweet. Hence the answer is (2).
In these questions, artificial or code values are assigned to a word or a group of words and the candidate is required to find out the original words.
Example : If in a certain language FLOWER is written as EKNVDQ, what will be written as GNTRD?
(1) HEOUS (2) HOUES (3) HUOSE (4) HOUSE (5) None of these
Each letter of the word is one step ahead of the corresponding letter of the code.
Thus HOUSE is written as GNTRD, So the answer is (4)
New Type of Coding
This is a kind of coding recently included in the Reasoning section. In this type of questions either alphabetical code values are assigned to symbols or symbols are assigned to alphabets. The candidate is required to analyse the code as per direction.
Example. In a certain code ‘TOME’ is written as @ $ * ? and ARE is written as • £ ? How can ‘REMOTE’ be written in that code?
(1) £ ? • $ @ ? (2) @ ? * $ @ ? (3)£ ? * $ @ ? (4)Cannot be determined
(5) None of these
Sol: From the data we have
T = D@ O = □$ M = □* E = ? and A = □• R = □£ E□?
Hence REMOTE is coded as £ ? * $ @ ?
So (3) is the answer.