Question

In a coding system, each letter in a word is replaced by the letter that is two positions ahead in the alphabet (e.g., A becomes C, B becomes D, ..., Z becomes B). If the word "CAT" is coded using this system, what will be the code for the word "DOG"?

Hint:

Remember: In coding-decoding, identify the pattern (e.g., shifting letters by a fixed number) and apply it consistently to each letter. Use alphabet positions (A=1, Z=26) for clarity.

Answer 1

Given: \[ \text{Word} = \text{DOG}, \quad \text{Rule: Each letter is replaced by the letter two positions ahead in the alphabet} \] Step 1: Understand the Coding Rule
The alphabet is A, B, C, ..., Z (positions 1 to 26). For each letter, the coded letter is the one two positions ahead:
- A (1) → C (3), B (2) → D (4), ..., Y (25) → A (27-26=1), Z (26) → B (28-26=2).
Thus, the position of the coded letter is \( \text{Original position} + 2 \), with wrapping around the alphabet (if position is more than 26, subtract 26).
Step 2: Code the Word "DOG"
Break down the word "DOG" into individual letters and apply the rule:
- D: Position 4 → \( 4 + 2 = 6 \) → Letter F
- O: Position 15 → \( 15 + 2 = 17 \) → Letter Q
- G: Position 7 → \( 7 + 2 = 9 \) → Letter I
So, "DOG" is coded as FQI.
Step 3: Verify with Example "CAT"
To ensure understanding, code "CAT" as given in the question:
- C: Position 3 → \( 3 + 2 = 5 \) → Letter E
- A: Position 1 → \( 1 + 2 = 3 \) → Letter C
- T: Position 20 → \( 20 + 2 = 22 \) → Letter V
Thus, "CAT" becomes ECV, confirming the rule is consistent. Now, check "DOG" again:
- FQI matches the calculation. Answer: The correct answer is option (1): FQI.