SSC JE Mechanical Engineering 2017 Set 5 Paper

Given,
Condition (1) A@B = A is the mother of B.
So R@S ⇒ R is the mother of S. R has only one child (given.) That is S.
Condition (2) A!B = A is the granddaughter of B.
So Q!R = Q is the granddaughter of R.
So R, Q’s grandmother. So S became the mother of Q.
Condition (3) A#B = A is the sister of B.
So P#Q = P is the sister of Q. So S is the mother of P.