Olympiad Test : Coding – Decoding - 1 - Class 6 MCQ

Each letter of the word ‘TRUTH’ is replaced by a set of two letters – one preceding it and the other following it – in the code. Thus, T is replaced by SU, R is replaced by QS and so on.

All the letters of the word, except the last letter, are written in a reverse order to obtain the code. 

Here,

Divide the given word into six sets of two letters each and label these sets from 1 to 6. Then the code contains these sets in the order 4, 3, 5, 2, 6, 1 with the letters of sets 3, 2, 1 written in a reverse order. Thus, we have:

Divide the word into three groups of two letters each and write the letters of each group in the reverse order.

Each letter in the word is replaced by the letter which occupies the same position from the other end of the alphabet, to obtain the code. 

All the letters of the word, except the last letter, are written in the reverse order and in the group of letters so obtained each letter is moved into steps forward to get the code.

Clearly, the sixth letter from the left in the code is L. 

Each letter of the word is five steps ahead the corresponding letter of the code.

The code has been obtained by writing the first four and the last four letters of the word in the reverse order. Thus, we have.

The code for OVER is MWEO.

Each letter is coded by the numeral obtained by subtracting from 27 then numeral denoting the position of the letter in the English alphabet. W, O, M, A, N are 23rd, 15th, 13th, 1st and 14th letters. So their codes are (27 – 23), (27 – 15), (27 – 13), (27 – 1), (27 – 14) 
i.e. 4, 12, 14, 26, 13 respectively. 

In the given code, Z = 1, Y = 2, X = 3, ……. C = 24, B = 25, Z = 26. 
So, GO = 20 + 12 = 32 and SHE = 8 + 19 + 22 = 49. 
Similarly, SOME = S + O + M + E = 8 + 12 + 14 + 22 = 56. 

Taking

Let A = 1, B = 2, C = 3, ……, Z = 26.
Now, M = 13 = (Remainder obtained after dividing by 9).
S = 19 = 1 (Remainder obtained after dividing by 9 twice)
T = 20 = 2 (Remainder obtained after dividing by 9 twice)
R = 18 = (Remainder obtained after dividing by 9)
So, MASTER = , POWDER =

The code for RENT is % + × . 

The code for CALICUT is 8251896. 

The code for INDIA is 63568. 

The code for GREECE is 381191.