In a certain code language, ‘A + B’ means ‘A is the mother of B’; ‘A − B’ means ‘A is the brother of B’; ‘A × B’ means ‘A is the wife of B’ and ‘A ÷ B’ means ‘A is the father of B’. Based on the above, how is S related to P if ‘P × Q ÷ R − S × A’?

Correct — C. Read the chain one symbol at a time, in the printed order.

P x Q means P is the wife of Q.
Q / R means Q is the father of R.
R - S means R is the brother of S.
S x A means S is the wife of A, so S is female.

R and S are siblings and R is Q's child, so S is Q's child too. P is Q's wife, so P is S's mother.

A female child of P is her daughter — option (c).

Why the others are wrong

• (a)
  Mother — This reverses the direction of the question. It asks how S stands to P, and P is the parent here, not S.
• (b)
  Son — S x A makes S the wife of A, so S is female. Son fails on that single link, even though S is correctly placed in the child generation.
• (d)
  Father — The father in the chain is Q, from Q / R. S belongs to the generation below, and S is female besides.

Symbol-coded relations are safest drawn rather than argued in prose. Put P and Q on one line as a couple, put R and S on the line below as their children, and mark S female.

Read every symbol in the order printed and stop at each one. The traps are all direction traps: A x B means A is the wife of B, not B the wife of A, and A / B means A is the father of B.

Then answer the question actually asked — how S stands to P, which runs from the lower generation to the upper.

Key facts

• P x Q makes P the wife of Q, so P is female.
• Q / R makes Q the father of R.
• R - S makes R and S siblings, and S x A makes S female.
• S is therefore a daughter of the couple P and Q.

Common traps

• Answering how P stands to S instead of how S stands to P.
• Missing that S x A is what settles S's gender.
• Treating brother-of as a one-way link and losing S from the child generation.

No directly related past PYQ was found.