Solving Coding-Decoding Problems

This type of question falls under coding-decoding or letter coding. In these problems, letters are assigned numerical values based on a specific pattern or rule. We are given example codes and need to use them to decode a new word.

Analyzing the Given Codes

We are given two examples of words coded into numbers:

• POSTER is coded as 592314
• DARK is coded as 8647

Our goal is to find the code for STROKE.

Finding the Letter-to-Code Mapping

Let's examine the first coded word, POSTER = 592314. We can infer the code for each letter by its position:

• P $\rightarrow$ 5
• O $\rightarrow$ 9
• S $\rightarrow$ 2
• T $\rightarrow$ 3
• E $\rightarrow$ 1
• R $\rightarrow$ 4

Now, let's look at the second coded word, DARK = 8647:

• D $\rightarrow$ 8
• A $\rightarrow$ 6
• R $\rightarrow$ 4
• K $\rightarrow$ 7

We can see that the code for the letter 'R' is 4 in both lists, which confirms that the mapping is consistent across the given words. We now have a unique numerical code for each relevant letter.

Coding the Word STROKE

Now we will use the mapping we found to code the word STROKE. We will replace each letter in STROKE with its corresponding numerical code:

• S $\rightarrow$ 2
• T $\rightarrow$ 3
• R $\rightarrow$ 4
• O $\rightarrow$ 9
• K $\rightarrow$ 7
• E $\rightarrow$ 1

Putting these numbers together in the order they appear in STROKE, we get the code:

S T R O K E

2 3 4 9 7 1

So, STROKE is coded as 234971.

Revision Table: Key Concepts in Coding-Decoding

Additional Information: Tips for Solving Coding Problems

Here are some helpful tips for tackling coding and decoding questions in exams:

• Analyze Examples: Carefully look at the given coded examples. Try to identify the pattern or rule being used. Is it letter shifting, reversing, direct substitution, or something else?
• Identify Unique Mappings: If numbers or symbols are used, check if each letter has a unique code or if the code depends on the letter's position.
• Check Consistency: If multiple examples are given, verify that the rule or mapping is consistent across all examples.
• List the Alphabet: For letter coding problems involving shifting, writing down the alphabet with its positions (A=1, B=2, ...) can be very helpful.
• Break Down the Target Word: Once you understand the rule, apply it letter by letter to the word you need to code or decode.
• Look for Common Letters: In mixed coding (sentence-based), identify words common to multiple statements to find their codes.
• Practice: Solving various types of coding-decoding problems will help you quickly identify patterns and apply rules.