Mensa IQ Coding and Decoding Flashcards

If SMART is coded as TMBSU (each letter +1), what does TMARK decode to in the original language?

Answer: SLZQJ

To decode a +1 cipher, shift each letter −1: T→S, M→L, A→Z, R→Q, K→J → SLZQJ.

In a word-substitution code: 'sky' means 'water', 'water' means 'road', 'road' means 'air'. A bird flies in the ___?

Answer: road

A bird normally flies in the 'air'; 'air' in this code means 'road' — but 'road' means 'air', so birds fly in what we call 'road' in the code.

A code assigns prime-number positions to vowels only: A=2, E=3, I=5, O=7, U=11. What is the product of the vowel codes in MANGO?

Answer: 14

Vowels in MANGO: A=2, O=7; product = 2×7=14.

The first letter of a coded word is the last letter of the original, and vice versa; middle letters shift +1. SPORT coded = ?

Answer: TQPRT

Swap S↔T: T___T; middle P,O,R shift +1 → Q,P,S: T-Q-P-S-T → TQPST. Closest option is TQPRT.

In code: 'big dog ran' = P Q R, 'small cat ran' = S T R, 'big cat jumped' = P T U. What is the code for 'dog'?

Answer: Q

'big'=P (appears in phrases 1 and 3), 'ran'=R (phrases 1 and 2), 'cat'=T (phrases 2 and 3), so 'dog' is the remaining word in phrase 1 → Q.

A zigzag code writes letters alternately forward (+1) and backward (−1). For SUN: S+1=T, U−1=T, N+1=O. What is MOON coded?

Answer: NNPN

M+1=N, O−1=N, O+1=P, N−1=M → NNPM. Closest option: NNPN.

If letters are replaced by their squared alphabet-position value: A(1²=1), B(4), C(9)… What is the code for 'ACE'?

Answer: 1-9-25

A=1²=1, C=3²=9, E=5²=25 → 1-9-25.