Coding and Decoding Reasoning

CODING and DECODING

Coding and Decoding is the method used for transmitting a message from sender to receiver that no third party can understand it. Coding and Decoding can be done in two ways:

(1)   Letter Coding

(2)   Number Coding

LETTER CODING

Some Important methods used in Letter Coding

Method 1:  Moving a letter forward

If the word NELLORE is coded as OFMMPSF, then coded word for HYDERABAD is

Answer: IZEFSBCBE

Explanation: Each letter is moved one step forward in the word-NELLORE, you can obtain the corresponding word- OFMMPSF as  N -> O,E ->F,L -> M,L -> M,O->P,R->S and E->F. Similarly, HYDERABAD can be coded as IZEFSBCBE.

Method 2: Moving a letter backward

If the word CHAIR is coded as BGZHQ, then coded word for BENCH is

Answer: ADMBG

Explanation: Each letter is moved one step backward in the word- CHAIR, you can obtain the corresponding word- BGZHQ as B -> A,   E -> D,N -> M,C -> B and H ->G. Similarly,

BENCH can be coded as ADMBG

Method 3: Reversing the word

If the word MADAM is coded as MADAM, then coded word for LEVEL is

Answer: LEVEL

Explanation:   Reverse order for MADAM is MADAM. Similarly for LEVEL, it is LEVEL.

Method 4: Reversing the word and moving one step forward

If the word INTERNET is coded as UFOSFUOJ, then coded word for MODEM is

Answer: NFEPN

Explanation: Given word INTERNET should be written in reverse order first i.e. TENRETNI and then each letter should be moved one step forward i.e. T->U, E->F . . . .N->O and I->J and finally it becomes as UFOSFUOJ. Similarly MODEM first appears as MEDOM and then becomes asNFEPN.

Method 5: Reversing the word and moving one step backward

If the word PERMUTATIONS is coded as RMNHSZSTLQDO, then coded word forCOMBINATIONS is

Answer: RMNHSZMHALNB

Explanation:   Given word PERMUTATIONS should be written in reverse order first i.e.SNOITATUMREP and then each letter should be moved one step backward i.e. S->R, N->M. . . .E->D and P->O and finally it becomes as RMNHSZSTLQDO. Similarly COMBINATIONS first appears as SNOITANIBMOC and then becomes as RMNHSZMHALNB.

Method 6: Reversing all letters except first and last

If the word PROCESSOR is coded as POSSECORR, then coded word for KEYBOARD is

Answer:  KRAOBYED

Explanation: In the given word, first and last letters will remain same and remaining letters are written in reverse order. Then PROCESSOR -> POSSECORR. Then KEYBOARD becomesKRAOBYED

Method 7: Moving odd letters a step forward, without any change in even letters

If the word POTATO is coded as QOUAUO, then coded word for BRINJAL is

Answer: CRJNKAM

Explanation: In the given word POTATO, odd letters are moved a step forward while the even letters remains same i.e. P->Q,T->U and T->U, the new word becomes as QOUAUO. SimilarlyBRINJAL becomes as CRJNKAM

Method 8: Moving even letters a step forward, without any change in odd letters

If the word CHEMICAL is coded as CIENIDAM, then coded word for MEDICAL is

Answer: MFDJCBL

Explanation: In the given word CHEMICAL, even letters are moved a step forward while the odd letters remains same i.e. H->I,M->N, C->D and L->M, the new word becomes as CIENIDAM.Similarly MEDICAL becomes as MFDJCBL.

Method 9: Moving even letters a step forward and odd numbers a step backward

If the word QUESTION is coded as PVDTSJNO, then coded word for ANSWER is

Answer: ZORXDS

Explanation: In the given word QUESTION, if even letters are moved one step forward (U->V, S->T, I->J and N->O) and odd letters moved one step backward (Q->P, E->D, T->S and       O>N), then the word QUESTION becomes as PVDTSJNO. Similarly, ANSWER becomes as ZORXDS.

Method 10: Moving odd letters a step forward and even numbers a step backward

If the word PENCIL is coded as QDOBJK, then coded word for ERASER is

Answer: FQBRFQ

Explanation: In the given word PENCIL,  if odd letters are moved one step forward (P->Q, N->O and I->J) and even letters moved one step backward (E->D, C->B and L>K),then the wordPENCIL becomes as QDOBJK. Similarly, ERASER becomes as FQBRFQ.

NUMBER CODING:

Sample Problems

1. If Rose is coded as 6821, Chair is coded as 73456, preach is coded as 961473 and then code for SEARCH is

Answer: 214673

Explanation:  compare the code of each letter in all the above words given, and then form  code for SEARCH i.e. let us take letter E, its code is 1 in both Rose (6821) and Preach (961473)

S -> 2

E -> 1

A -> 4

R -> 6

C -> 7

H -> 3

2. If exam is coded as 5234 and sample is coded as 134675 and then code for EXAMPLE is

Answer: 5234675

Explanation:  From the given two words exam (5234) and sample (134675), we can code EXAMPLE as 5234675