Understanding the Code Language

The problem describes a specific code language where words are converted into a sequence of numbers. We are given two examples to help us figure out the rule:

• 'CHILD' is coded as '6169248'
• 'GUEST' is coded as '142153840'

We need to apply the same rule to find the code for 'BOOK'.

Analyzing the Encoding Pattern

Let's look at the letters in 'CHILD' and their corresponding alphabetical positions:

• C is the 3rd letter.
• H is the 8th letter.
• I is the 9th letter.
• L is the 12th letter.
• D is the 4th letter.

The code for 'CHILD' is '6169248'. Let's try to see if there is a pattern between the letter positions and the code digits. The code sequence '6169248' can potentially be broken down into parts corresponding to each letter.

Let's consider the alphabetical positions: 3, 8, 9, 12, 4.

Comparing with the code parts: 6, 16, 9, 24, 8.

• C (3) → 6
• H (8) → 16
• I (9) → 9
• L (12) → 24
• D (4) → 8

It appears that most letters are encoded by doubling their alphabetical position: $3 \times 2 = 6$, $8 \times 2 = 16$, $12 \times 2 = 24$, $4 \times 2 = 8$. However, 'I' (9) is encoded simply as '9', which is its position value without doubling.

Now let's check the second example, 'GUEST', and its code '142153840'. The alphabetical positions are:

• G is the 7th letter.
• U is the 21st letter.
• E is the 5th letter.
• S is the 19th letter.
• T is the 20th letter.

The alphabetical positions are: 7, 21, 5, 19, 20. The code '142153840' seems to break down into parts corresponding to these letters:

• G (7) → 14 ($7 \times 2$)
• U (21) → 21 (21, not doubled)
• E (5) → 5 (5, not doubled)
• S (19) → 38 ($19 \times 2$)
• T (20) → 40 ($20 \times 2$)

This confirms the pattern observed with 'CHILD'. The letters 'I', 'U', and 'E' are vowels (A, E, I, O, U). It appears that consonants are encoded by doubling their alphabetical position, while vowels are encoded by their alphabetical position directly.

Applying the Code Rule to 'BOOK'

Now let's apply this rule to the word 'BOOK'. The letters and their alphabetical positions are:

• B is the 2nd letter.
• O is the 15th letter.
• O is the 15th letter.
• K is the 11th letter.

Let's determine if each letter is a consonant or a vowel and apply the rule:

• B (2): Consonant. Code = $2 \times 2 = 4$.
• O (15): Vowel. Code = 15.
• O (15): Vowel. Code = 15.
• K (11): Consonant. Code = $11 \times 2 = 22$.

Combining the codes for each letter, we get 4, 15, 15, 22. Written as a single number sequence, this is '4151522'.

The final code for 'BOOK' is '4151522'.

Conclusion

Based on the pattern derived from the examples 'CHILD' and 'GUEST', the word 'BOOK' is coded as '4151522' in the given language.

Revision Table: Code Language Logic

Additional Information: Coding-Decoding Concepts

Coding-Decoding is a common topic in logical reasoning where messages or words are encoded using a specific rule or pattern. To solve such problems, you need to:

• Observe the given examples carefully.
• Identify the pattern or rule applied for encoding/decoding. This might involve:
  • Shifting letters (e.g., A becomes B, B becomes C).
  • Using alphabetical positions.
  • Applying mathematical operations to positions (addition, subtraction, multiplication, division).
  • Reversing the order of letters or codes.
  • Using opposite letters (e.g., A → Z, B → Y).
  • Combining multiple rules.
• Apply the identified rule to the word or message you need to encode or decode.

Practice with different types of coding-decoding questions helps in quickly identifying the underlying logic.