Question 1

A + B: A is the father of B; A − B: A is the mother of B; A × B: A is the brother of B. What does X × Y + Z − W mean?

Accepted Answer

Solution: Y is W's grandfather. X is Y's brother, Y is Z's father, Z is W's mother; W's sex is not given.

Question 2

With + brother, − sister, × father: which expression means C is the son of M: M−N×C+F, F−C+N×M, N+M−F×C or M×N−C+F?

Accepted Answer

Solution: M×N−C+F. M is the father of N; N is C's sister; C is F's brother, so C is male.

Question 3

\father, mother, % brother, @ son. How is A related to E in A \ B C % D @ E?

Accepted Answer

Solution: father-in-law. B is the mother of C and D; D is the son of E, a different person from B, so E is B's husband; A, B's father, is E's father-in-law.

Question 4

What are the common traps in Coded relations (A@B means...) questions?

Accepted Answer

Reversed symbols: if "A % B means B is the niece of A", the niece is on the right. Unfixed sex: P & R @ Q (R is P's mother, R married to Q) makes P Q's child, but son or daughter cannot be decided. Distinct letters: without "different letters are different people", E in Example 3 could be B herself.

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