If A + B means A is the brother of B; A % B means A is the father of B and A x…

In coded blood-relation puzzles, every symbol first decodes to one direct relation (brother, father, or sister). To reach a compound relation such as "uncle," chain two or more direct relations so that one person becomes a parent, and check whether the letter you started from is that parent's sibling of the correct gender (a father's brother is the paternal uncle).

Working link by link, rather than guessing from the final answer, is the reliable method, since misreading a single symbol reverses the entire relationship.

Decoding M + K % T x P:

1. M + K means M is the brother of K.

2. K % T means K is the father of T.

3. T x P means T is the sister of P, so T and P share the same father, K.

4. Since K is the father of P and M is K's brother, M is the father's brother of P - that is, the paternal uncle of P.

Cross-check with a quick family sketch: K and an unnamed parent have two children, T and P; M is K's sibling (brother). By definition, a father's brother is the paternal uncle, so M is indeed the uncle of P - confirming the chain above independently.

Why the other codings fail:

• M % N x P: M is the father of N, and N is the sister of P (same father, M) - this makes M the direct father of P, not the uncle.

• N x P % M: N is the sister of P, and P is the father of M - this reverses the generations, placing P as M's father rather than describing M as P's uncle.

• M + S % R % P: M is the brother of S, S is the father of R, and R is the father of P - this is one generation too many; S (M's sibling) becomes P's grandfather, making M the grand-uncle of P, not the uncle.

So the coding that correctly places M as the uncle of P is M + K % T x P.