In a Venn diagram, if a triangle represents 'hostel', a circle represents 'college', a hexagon represents 'canteen', a rectangle represents 'library', and a square represents 'transport', what does the letter 'P' located at the intersection of only the circle, triangle, and hexagon represent?

In a Venn diagram consisting of a rectangle, a circle, and a triangle, if the region enclosed by both the rectangle and the circle but not by the triangle is labeled with a specific number, and that number is 4, which option correctly identifies this value?

In a certain Venn diagram representing professional and demographic categories, if a triangle represents doctors, a rectangle represents women, and a circle represents postgraduates, which region representing the intersection of all three shapes gives the total number of postgraduate female doctors as 15?