Question

In a certain code, TERMINAL is written as SDQLJQBM. How is CREDIBLE written in that code?

• A. BQDCJCMF
• B. BQDCHAKD
• C. DSFEJCMF
• D. DSFEHAKD

Hint:

When cracking a cipher from one example, map each letter's shift and look for position-wise patterns (first half vs. last half, alternating shifts, etc.). Then consistently apply that pattern to the new word and check against options.

Answer 1

The Correct Option is A

Step 1: Infer the rule from the example.
TERMINAL \(\rightarrow\) SDQLJQBM
Write positions (\(A=1,\ldots,Z=26\)):
T(20)\(\to\)S(19) \(-1\), E(5)\(\to\)D(4) \(-1\), R(18)\(\to\)Q(17) \(-1\), M(13)\(\to\)L(12) \(-1\)
I(9)\(\to\)J(10) \(+1\), N(14)\(\to\)Q(17) \(+3\), A(1)\(\to\)B(2) \(+1\), L(12)\(\to\)M(13) \(+1\). \smallskip Observed pattern: First four letters \(\Rightarrow -1\) each; last four letters \(\Rightarrow\) mostly \(+1\), with \(N\) (at/after midpoint) advancing \(+3\). Applying this observed mapping to a new word means: • For the first four letters: shift back by 1.
• For the last four letters: shift forward; letters in the lower half (A–M) move \(+1\) (as seen for I, A, L), while \(N\) moved further to \(Q\) (here there is no \(N\) in the target word; we'll mimic the I/A/L pattern: \(+1\)). Step 2: Apply the rule to CREDIBLE.
Split: C R E D \, | \, I B L E.
First four (\(-1\)): C\(\to\)B,\ R\(\to\)Q,\ E\(\to\)D,\ D\(\to\)C \(\Rightarrow\) BQDC.
Last four (use \(+1\) like I/A/L in the example): \ I\(\to\)J,\ B\(\to\)C,\ L\(\to\)M,\ E\(\to\)F \(\Rightarrow\) JCMF. Step 3: Conclude.
Encoded form \(=\boxed{\text{BQDCJCMF}}\).