A + B means A is the mother of B, A ÷ B means A is the father of B, A − B means A is the sister of B, A × B means A is the brother of B. What does P ÷ Q − R mean?

Correct — C.
Rule: decode each symbol as a relation from the left name to the right.

P ÷ Q: P is the father of Q.
Q − R: Q is the sister of R, so Q and R share parents.
So P is R's father as well → option (c).

Why the others are wrong

• (a)
  P is R's uncle — P is R's uncle would need P to be the brother of R's parent. P ÷ Q makes P a parent of R's sister, and so of R.
• (b)
  Q is R's mother — Q is R's mother needs Q + R. The printed sign between Q and R is −, which makes Q R's sister.
• (d)
  R is P’s mother — R is P's mother runs the wrong way. P is the father of Q and R, so R is P's child, a generation below.

Coded relations turn a symbol into a relation between the name before it and the name after it. Read the expression one symbol at a time and write each link down.

Here the links are P ÷ Q (father) and Q − R (sister). The second makes Q and R siblings, so whoever is Q's parent is R's parent too.

Key facts

• In this question: + is mother, ÷ is father, − is sister, × is brother.
• P ÷ Q − R reads: P is Q's father, and Q is R's sister.
• A sibling's parent is your own parent.

Common traps

• Reading the symbols right to left, so that R becomes P's relative instead of the other way round
• Choosing uncle because P is male and one generation above R

No directly related past PYQ was found.