Have given, Condition (1) ⇒ A @ B = A is the mother of B. So Z@W = Z is the mother of W. Condition (2) ⇒ A # B = A is sister of B. So Y#Z = Y is sister of Z. Condition (3) ⇒ A! B = A is the daughter of B, So X!Y = X is the daughter of Y. That is, Y will be the mother of X. Because Y is sister of Z. So Z is maternal aunt of X.