Reasoning : Logical Reasoning & Analytical Ability

Q 173 / 325

UPSC CSE Prelims 2017

Consider the following:

A + B means A is the son of B.
A – B means A is the wife of B.
What does the expression P + R – Q mean?

EXPLANATION

Correct Option (3)

The given relational definitions are:

  • A + B means A is the son of B.
  • A - B means A is the wife of B.

Applying these rules to the expression P + R - Q:

  • From P + R: According to the first rule, P is the son of R. This establishes P as male and R as a parent of P.
  • From R - Q: According to the second rule, R is the wife of Q. This establishes R as female and Q as male (husband of R).

Combining these deductions:

  • P is the son of R.
  • R is the wife of Q.

Therefore, R is the mother of P, and Q is the husband of R. Consequently, Q is the father of P.

Incorrect Options:

Based on the derived relationship that Q is the father of P:

  • Option 1 (Q is the son of P) is incorrect, as Q is the father, not the son, of P.
  • Option 2 (Q is the wife of P) is incorrect, as Q is male and the father of P, not the wife.
  • Option 4 (None of the above) is incorrect because option 3 accurately represents the relationship between Q and P.