CODING - DECODING
The term Coding-Decoding primarily relates with message sent in secret form which can not be understood by others
easily. Coding, therefore, means rule or method used to hide the actual meaning of a word or group of words and
decoding means the method of making out the actual message that is disguised in coding .
Category I
In this category of questions, a word is coded by simplychanging the order of letters of the word.
# EXAMPLES #
Ex.1 In a code language if TRAINS is coded as RTIASN, how PISTOL will be coded in the same language ?
(A) SITLOP (B) IPSTLO
(C) SIPTLO (D) IPTSLO
Sol. If we compare the basic word {TRAINS} with the coded word {RTIASN}, we would see that the letters used in
the word are same as in the basic word but their order of placement has been changed. Letter T at first position of
basic word has been placed at second position in the coded word & letter R at second position has been placed in the first position.
It means that in this question, letters of the basic word have been interchanged i.e., first letter with second, third with the fourth
and so on. And thus we get the coded word. In this code language word, PISTOL will be coded as IPTSLO. Hence, option (D) is our answer.
In this category of questions, letters of a word are substituted for either a new letter or a numeric. And the same substitution
helps to find out the coding of the word in questions. This substitution of letters may either be direct or in a jumbled up fashion.
(A) Direct Substitution
Ex.2 In a code language if SUGAR is coded as PKLTN and TEA is coded as QGT, how
would you code GREAT in the same code language ?
(A) ENGTP (B) LNGTK
(C) LNGTQ (D) LNGQT
Sol. 
Here we see that S is substituted for P, U for K, G for L, A for T & R for N. And in the word TEA. T is substituted
for Q, E for G and A for T. Now we find that coding for letter A in SUGAR is T and coding for letter A in TEA is also
T. This implies that substitution of letter in coded word takes place in the same order as in basic word. In simple words,
in the word SUGAR letter S in the basic word has been substituted for a new letter and coded at first place in the coded
word, U at the second place, G at the third place and so on.
When letters of a word are substituted for the new letters and are placed in the coded word at the same position as in
the basic word then this method of substitution is called direct substituion.
Therefore, code for GREAT will be LNGTQ. Hence, option (C) will be our answer.
Ex.3 In a code language if TEARS is coded as VWXYZ and MAN is coded as 123 then how would you code RESENTMENT in that language?
(A) YWZW3V1W3Y (B) YWZ3WV1W3Y
(C) YWZW3V1WY3 (D) YWZW3V1W3V
Sol. This questions is of direct substitution method. Letters of the basic words are substituted as under.
Therefore, the coding for the word RESENTMENT will be YWZW3V1W3V. Hence, option (D) is our answer.
Ex.4 If TEARS is coded as VWXYZ, then how would you code BEAS in that language ?
(A) YWXZ (B) VWXZ
(C) MWXZ (D) WVZY
Sol. 
Using the same coding pattern for BEAS, we get W for E, X for A & Z for S but code for B can not be determined as
it is absent in the basic word. Now we shall take the help of options. In option (A) we get W, X, Z for E, A & S respectively
which is correct but coding for B can not be Y as it is the coe for R. Likewise in option (B). V can not be coded for B as it is
the code for T. In option (C) we see that code for B is M which seems to be correct as it has not been used as a code for any
of the letters in basic word. Hence, code for BEAS would be MWXZ. Therefore option (C) is our answer.
(B) Substitution in mixed up fashion
Rule applied in this type of questions follows the same pattern as used in type (A) – Direct substitution but with slight
modification. Here also in this type each letter of basic word is substituted for a new letter but it may not necessarily be placed
in the same position in coded word as it occupies in the basic word. In simple words, it implies that coded letter at first position
in basic word does not necessarily occupy the first position in the coded word. It can be placed at any place in the coded word.
Ex.5 In a code language, if BEAT is coded as 5642 and SWEET is coded as 66912, how would you code TEASE ?
(A) 96162 (B) 56264
(C) 96625 (D) 55296
Sol. 
Coding pattern used in the above question substitution for the letters has not been used directly. Code for E seems to
be 6 in BEAT whereas it carries code 9 and 1 in the word SWEET which apparently appears to be incorrect because in
substitution method same letter carries same code even if it appears in different word.
Now in word SWEET letter E appears twice and in its coding numeric 6 appears twice. Thus it is confirmed that code
for E is 6. It may be concluded from the coding pattern used here that letters of the words BEAT and SWEET have been
substituted for numeric in jumbled up form. Word BEAT and SWEET share common letters E and T and their coding share
common numeric 6 and 2. Therefore, E is coded as 6 and T is coded as 2. It means that the code for TEASE will definitely
have 6 6 & 2 for E, E and T. Code for A and S has yet to be found out.
Now from word BEAT and SWEET again, we see that code for A in word BEAT should be either 5 or 4 (leaving 6 & 2 for E and T).
Similarily, code for S should be either 9 or 1 (leaving 6 & 2 for E and T). We shall not take the help of options to answer the code for TEASE.
(A) It cannot be the code for TEASE as code for A (5 or 4) is not available.
(B) It cannot be the code for TEASE as code for S (9 or 1) is not available.
(C) It may be the code for TEASE as besides 662 code for EE and T, we get 5 probable code for A and 9 probable code for S. Hence, option (C) is our answer.
Category III
In this category, rule of coding is of entirely different type from what has been discussed so far in category I and II.
IN this type, word is coded, replacing each letter of the word by a new word from the alphabets
(A ...... Z) on the basis of a particular method. It has been explained in the following examples -
Ex.6 If temple is coded as VHQURL, how would you code CHURCH ?
(A) EKYWIO (B) EKUWIO
(C) EKYWIN (D) EKYWJO
Sol. 
Code for T is V, for E it is H, for M it is Q. It may be noticed from here that letters of TEMPLE have been replaced
by new letters from the alphabets.There is a gap of one letter between T and V, gap of two letters between
E and H, gap of three letters between M & Q and so on in the alphabets.
Therefore, coding for CHURCH is
C H U R C H
+1 +2 +3 +4 +5 +6
E K Y W I O
Hence (A) is our answer.
Ex.7 If TEMPLE is coded as VHQNIA, how would you code CHURCH ?
(A) EKYWI (B) EKYQZD
(C) EKYPZD (D) EKYQWD
Sol. Coding for TEMPLE is
T E M P L E
+1 +2 +3 –1 –2 –3
V H Q N I A
Here, the first half of the letters of the word TEMPLE have been replaced with new letters from the alphabets
with a gap of 1, 2 & 3 letters respectively in forward direction, and second half of the letters of the word have been
replaced by new letters from the alphabets with a gap of 1, 2 and 3 in backward direction. Hence, code for word
CHURCH would be EKYPZD. Hence, (C) is our answer.
Directions : (Ex. 8 to 10)
The number in each question below is to be codified in the following code
Ex.8 184632
(A) MDJBSI (B) MDJBIL
(C) MDJBWL (D) MDBJIL
Sol. As given 1 is coded as M, 8 as D, 4 as B, 6 as J, 3 as I and 2 as L. So, 184632 is coded as MDBJIL.
Ex.9 879341
(A) DWNIBS (B) DWNBIM
(C) DWNIBM (D) NDWBIM
Sol. As given 8 is coded as D, 7 as W, 9 as N, 3 as I, 4 as B and 1 as M. So, 879341 is coded as DWNIBM.
Ex.10 64928
(A) JBNLD (B) JBLND
(C) BJNLD (D) DBNLS
Sol. As given , 6 is coded as J, 4 as B, 9 as N, 2 as L and 8 as D. So, 64928 is coded as JBNLD.
Directions : In each of the following questions below, find out the correct answer from the given alternatives.
ASSIGNMENT
Q.1 In a certain code, INSTITUTION is written as NOITUTITSNI. How is PERFECTION written in that code ?
(A) NOICTEFREP (B) NOITCEFERP
(C) NOITCEFRPE (D) NOITCEFREP
Q.2 In a certain code, GIGANTIC is written as GIGTANCI. How is MIRACLES written in that code ?
(A) MIRLCAES (B) MIRLACSE
(C) RIMCALSE (D) RIMLCAES
Q.3 In a certain code, GOODNESS is coded as HNPCODTR. How is GREATNESS coded in that code ?
(A) HQFZUODTR (B) HQFZUMFRT
(C) HQFZSMFRT (D) FSDBSODTR
Q.4 In a certain code, EXPLAINING is written as PXEALNIGNI. How is PRODUCED writtenin that code ?
(A) ORPBUDEC (B) ROPUDECD
(C) ORPUDECD (D) None of these
Q.5 If FESTIVAL is coded as MBWJUTFG, then OPIUM would be coded as -
(A) NOHTL (B) NTHNO
(C) NVJQP (D) MUIPO
Q.6 If LINGER is 123456 and FORCE is 56789, then FIERCE is -
(A) 345667 (B) 456678
(C) 345677 (D) 556789
Q.7 If CLOTHES is EXHAUST and THRICE is STABLE, then SHIRT is -
(A) BLUSH (B) STAUL
(C) THULE (D) BLASH
Q.8 In a certain code, PRODUCTS is written as NPMBSARQ. How is COMPREHENSION written in that code ?
(A) AMKNPCFCLOMLQ
(B) AMKNPCFCLQGML
(C) AMKNPCFCLQGNL
(D) AMKNPCFCKOML
Q.9 In a certain code, BOY is written as $* · and HOUR is written @*£0. How is RUBY written in that code ?
(A) 0 £ $ · (B) 0 $ £ ·
(C) · $ £ 0 (D) · £ $ 0
Q.10 In a certain code language, QUEUE is written as Q 22, and CHURCH is written as 1 UR1. Which of the following would be most appropriate code for BANANA in that language ?
(A) B5A5 (B) 5N5A
(C) B55A (D) BA5A5A
Q.11 In certain code, BOXER is written as AQWGQ. How VISIT is written in that code ?
(A) UKRKU (B) UKRKS
(C) WKRKU (D) WKRKS
Directions (12-16) :
In the following questions, two columns
I and II have been given. In column I few words are given and in column II their codes have been
given using a particular rule. The order of the smaller letter have been placed in jumbled up form. You
have to decode the language and choose the alternative which is equal to letter asked in the question.
Column I Column II
(1) DESIGN (A) uklbjz
(2) INFORM (B) cbxkqy
(3) MOTHER (C) ygzwxc
(4) RIGHTS (D) bjucgw
(5) TAILOR (E) wcpybv
(6) GARDEN (F) vzcjlk
Q.12 What is the code for letter N ?
(A) u (B) k
(C) c gg(D) g
Q.13 What is the code for letter F ?
(A) l (B) b
(C) q (D) g
Q.14 What is the code for letter O ?
(A) y (B) k
(C) v (D) c
Q.15 What is the code for let ter S ?
(A) z (B) w
(C) u (D) x
Q.16 What is the code for letter G ?
(A) l (B) p
(C) b (D) j
Directions : (Q. 17 to 25)
In a certain language, the numberas coded as follows :
How are the following figures coded in that code ?
Q.17 421665
(A) AQRBBG (B) PQBRSE
(C) ASGRBE (D) QRPSSE
Q.18 67825
(A) BESGJ (B) BSEJG
(C) BESJG (D) BSEGJ
Q.19 55218
(A) GJGRS (B) GGJSR
(C) GGRJS (D) GGJRS
Q.20 91352
(A) PRWGJ (B) PRGWJ
(C) RPGWJ (D) RGPWJ
Q.21 720435
(A) EJMAGW (B) MAGJRW
(C) EJMAWG (D) MGARJW
Q.22 6650
(A) BBMG (B) BBGM
(C) BGMB (D) BMGB
Q.23 3215
(A) WJRG (B) WJGR
(C) JWRG (D) JWGR
Q.24 67852
(A) BSEJG (B) BESJG
(C) BSEGJ (D) BESGJ
Q.25 439216
(A) PQRWAB (B) AQRWPB
(C) APWQRB (D) AWPQRB
ANSWER KEY
1) D 2) B 3) B 4) D 5) C 6) B 7) D 8) B 9) A 10) C 11) B 12) B 13) C
14) A 15) C 16) D 17) A 18) C 19) D 20) A 21) C 22) B 23) A 24) D 25) D