Coding-Decoding and Blood Relations for Placements
letter coding, forward shift, backward shift, reverse alphabet, blood relation trees, direction sense, family tree method
Coding-Decoding and Blood Relations for Placements
Coding-decoding and blood relations are standard components of the logical reasoning section in placement aptitude tests. These questions test your ability to decode systematic rules and map family relationships accurately — both skills critical for systems thinking in technical roles where pattern recognition and logical structure are highly valued.
Coding-Decoding Approach
Test five standard encoding rules in order: forward shift (each letter moves forward by a fixed count), backward shift, reverse alphabet (A maps to Z, B maps to Y), positional reversal of letters in the word, and alternating patterns applied to odd and even positions separately. Compare the first two or three letter pairs from the given example to identify the shift value or rule quickly before verifying with the remaining letters.
Blood Relations — Family Tree Method
Always draw a family tree on paper for blood relation problems — never attempt to solve them mentally. Label each person with M for male or F for female wherever gender is explicitly stated. Do not assume gender from names alone. Connect family members with lines and label each connection. Trace the required relationship by walking the tree from one named person to the other person in the question.
Solved Example
In a code, PENCIL is written as RGPEKN. Comparing letter by letter: P maps to R (plus 2), E maps to G (plus 2), N maps to P (plus 2), C maps to E (plus 2), I maps to K (plus 2), L maps to N (plus 2). Rule is forward shift by 2. Applying to ERASER: E maps to G, R maps to T, A maps to C, S maps to U, E maps to G, R maps to T. Answer: GTCUGT.
Interview Tips
For blood relation problems the family tree is not an aid — it is the answer. Draw it every time without exception. For coding-decoding, forward and backward shift rules account for the majority of placement questions. Identify the shift value from the first two letter pairs and verify on the third before applying to the target word.