**CODING AND DECODING**

Coding is a “System of Signals ” used to express message between two persons , which cannot be understood buy any third person. The coded message is decoded by the receiver using rule which was used to code the message. Thus Coding – Decoding test ability of student to decode the message.

In these types of questions coded form are given with decoded message to find the rule of coding and then we need to decode the given words in question.

Coding can be done in many e.g individual alphabet or number. The code of a particular letter can be followed . It could also be jumbling of letters of meaningful word to generate code.

Some of the type of Code : $\\$ a)** Based on Alphabet** $\\$ $*\qquad $ Consist of jumbled letters of given word. $\\$ $ * \qquad $ Based on letters in a sequence.$\\$ b)

**. $\\$ $* \qquad $ Based on common words in group of words or sentence are coded. $\\$ c)**

*Based on group formation of words***. $\\ $$*\qquad $ Words or sentence is coded as a digits based on the common word. $\\$ d)**

*Based on Digits***$\\$ * $ \qquad $ Symbols and notations are used for coding words.**

*Based on Symbols.***Example 1 **:- In a code GATE is written as FBSF and SHOP is written as RIPQ then LAKE will be written as $\\$ $(a)\,$ MZLD $ \qquad (b)\,$ KBJF $\qquad (c)\,$ $ MZDL $ $\qquad (d)$ $\, KBFJ $ $\\$ **Answer :-** (b) $\\ $ $\qquad $ Letter at odd place code is letter before that in alphabet series.

**Example 2 :-** If E = 10 and BAT =46 then CAT will be $\\$ $(a)\,$ 48 $ \qquad (b)\,$ 49 $\qquad (c)\,$ $50 $ $\qquad (d)$ $\, 52 $ $\\$ **Answer :-** (a) $\\$ E is positioned at 5 in alphabet : E =2 *(5) = 10 $\\$ B is at 2 , A is 1st , T at 20 $ \therefore \; $ BAT= 2 (2 + 1 + 20) = 46; $\\$ Hence C at 3 ; A is 1 , T at 20 $\therefore \; $ CAT = 2(3 + 1 + 20) = 48 .

**Example 3 :-** If HOME is 2315 ; SHOP is 4238 ; WORK is 1367 then SMOKE is ?$\\$ (a)23175$\qquad (b)$27135 $\qquad (c)$43175 $\qquad (d)$ 41375 $\\$ **Answer :-** (d) $\qquad \begin{array}{|C|C|C|C|C|C|C|C|C|} \hline H&\bbox[yellow,5px]{O}&\bbox[yellow,5px]M&\bbox[yellow,5px]E&\bbox[yellow,5px]{S}&P&W&R&\bbox[yellow,5px]K \\ 2&3&1&5&4&8&9&6&7\\\hline \end{array}$

**Example 4:-** If water is called blue , blue is called red , red is called white , white is called sky , sky is called bird , bird is called green , green is called air then what is the color of light signal is used to stop the moving traffic ? $\\$ (a) Red $ \qquad (b)$ Air $\qquad (c)$ White $\qquad (d) $ Bird $\\$ **Answer :- ** ( C) $\\$ Red color light is used to stop moving traffic and in the coded question Red is White