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 411 students.

Show answer & explanation

Correct answer: A

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 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. I = J means J is the father of I. Thus J is father of I and H is mother of I, 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.

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.

Explore the full course: Tcs Preparation