In the figure, which number indicates doctors who are not married?

The correct answer is Option (3) → 1

A number belongs to every shape it lies inside. Doctors who are not married lie inside the triangle (doctors) but outside the square (married people).

• 1 — inside the triangle only: doctors who are neither married nor professors

• 5 — inside the triangle and the circle but outside the square: unmarried doctors who are also professors (not among the options)

• 2 and 6 lie inside the square, so they are married doctors; 4 lies outside the triangle, so it is not doctors at all