Coding and Decoding Reasoning Tricks, Questions, Videos

What is Coding and Decoding?coding decoding

Coding is a method of transmitting a message between the sender and the receiver that no third person can understand it. The coding and decoding one’s ability of deciphering the rule and breaking the code to decipher the message will be tested to know.
In this chapter we cover 2 section of Coding and Decoding, first is Letter Coding, Number Coding and then Substitution. Now first we are mentioning few points to remember before doing this section.

  1. Observe alphabets or numbers given in the code keenly.
  2. Find the sequence it follows whether it is ascending or descending.
  3. Detect the rule in which the alphabets/numbers/words follow.
  4. Fill the appropriate letter/number/word in the blank given.

Letter coding: Alphabets in a word are replaced by other alphabets according to a specific rule to know its code. So the common rule should be detected first. Some examples are given below:

  1. ‘ZYXW’ as coded as ‘ABCD’ then ‘STUV’ is coded as _______
    Method: Z – A, Y– B, X – C, W – D
    V – E, U – F, T – G, S – H
    Answer = HGFE
    Rule = Front Alphabet= Back Alphabet.
  2. ‘ bcd’ is coded as ‘def’ then ‘True’ is coded as __________
    Method: b – d (+2)
    c – e (+2)
    d – f (+2) +2 letters are considered in this code. True – Vtwg
    Answer = Vtwg.
  3. ‘ Hyderabad ’ is coded as ‘Ixedszcze’ then ‘Chennai’ is coded as..............
    Method: H – I (+1)
    Y – X (1–)
    D – E (1+)
    E – D (1-)
    R – S (1+)
    A – Z (1–)
    B – C (1+)
    A – Z (1– )
    D – E (1+)
    Here if we observe alternatively the letter increasing and one letter decreasing.
    Chennai =dgfmozj
    Answer = dgfmozj

Number coding: In this each alphabets or words are assigned to the numeric values we should observe the given letters and the assigned values and use the same rule to find the value to of given code. Please click for more details

Substitution: In this section an object names are substituted with different object names. We should carefully trace the substitution and answer given question.

1) 'book' is coded as ‘pencil’, ‘pencil’ is coded as ‘mirror’, ‘mirror is coded as ‘book’. Then what is useful to write on a paper?

Answer: Pencil is coded as mirror
Answer = mirror.

2) ‘man is coded as ‘woman’, woman is coded as ‘girl’, ‘girl’ is coded as ‘boy’, ‘boy’ is coded as ‘worker’ then 6 years female is known as?

Answer: 6 years female = girl, but ‘girl’ is coded as ‘boy’.
Answer = boy.

3) ‘Reds’ are ‘blues’, ‘blues’ are ‘whites’, ‘whites’ are ‘yellows’, ‘yellows’ are ‘oranges’, ‘oranges’ are ‘pinks’, then what is the colour of the sky?

Answer: Sky is blue, but blues are whites
Answer = white.


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Please comment on Coding and Decoding Reasoning Tricks, Questions, Videos


  1. Swaroop kumar

    Risesning compressive

  2. Ashwini

    Sun=15, moon=31, star=?


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