A = B means B is the father of A; A * B means A is the sister of B; A ? B…

2026

A = B means B is the father of A; A * B means A is the sister of B; A ? B means B is the mother of A;
A $ B means A is the brother of B; A @ B means B is the son of A; and A × B means A is the daughter of B.
Then which of the following is not correct?

  1. A.

    E $ F * G means G is the sister of E

  2. B.

    P × R ? Q means P is the granddaughter of Q

  3. C.

    G * H @ I = J means J and H are the husband and wife

  4. D.

    X = Y ? Z means Z is the grandmother of X

Attempted by 417 students.

Show answer & explanation

Correct answer: A

Concept: In these symbol-coded family-relation puzzles, chaining two relation symbols pins down a specific gendered relation (brother, sister, son, daughter, father, mother, grandmother, granddaughter, husband/wife) only when every step in the chain fixes gender. If one step only establishes a same-generation link without fixing gender (for example, brother + sister), the chain proves just a sibling relation — asserting a specific gendered label beyond that is not justified.

Meanings recap:

  • A = B → B is the father of A

  • A * B → A is the sister of B

  • A ? B → B is the mother of A

  • A $ B → A is the brother of B

  • A @ B → B is the son of A

  • A × B → A is the daughter of B

Analysis of each given statement:

  • E $ F * G: E $ F means E is the brother of F. F * G means F is the sister of G. Combining these, E and G are siblings, but G's gender is not specified. Therefore the claim that G is the sister of E is not justified (only the sibling relation is certain).

  • P × R ? Q: P × R means P is the daughter of R. R ? Q means Q is the mother of R. So Q is the grandmother of P, and P is the granddaughter of Q. The statement is correct.

  • G * H @ I = J: G * H means G is the sister of H. H @ I means I is the son of H (H is a parent of I, gender not yet fixed). I = J means J is the father of I. By the standard one-father/one-mother convention used in these puzzles, since J is already I's father, H must be I's mother. So J and H are husband and wife. The statement is correct.

  • X = Y ? Z: X = Y means Y is the father of X. Y ? Z means Z is the mother of Y. Therefore Z is the mother of X's father, i.e., Z is the grandmother of X. The statement is correct.

Cross-check: In every other option, the chain relies on relations that inherently fix gender (daughter, mother, son, father), so the outcome is forced. Only the brother + sister chain in this option leaves gender undetermined, confirming it as the one statement that cannot be validated.

Conclusion: The incorrect statement is "E $ F * G means G is the sister of E" because only a sibling relationship between E and G is certain; G's gender is not determined.

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