In the following figure triangle represents 'girls', square players and…

In a Venn diagram with three overlapping sets, every labeled region corresponds to one unique combination of membership in each set. To find the region for 'in set A and set B, but not in set C', locate the area that lies inside both A and B, then exclude whatever part of that also lies inside C.

Here the triangle stands for Girls, the square stands for Players, and the circle stands for Coach.

1. The region must lie inside the triangle (Girls) — this rules out the regions that never touch the triangle.

2. The region must also lie inside the square (Players) — this rules out the region that is inside the triangle but outside the square.

3. The region must lie outside the circle (Coach) — this rules out the region that is inside all three shapes.

4. The only region inside both the triangle and the square, and outside the circle, is Q.

Cross-check by testing each region against all three conditions (girls, players, not coach):

• P is inside the triangle only — satisfies 'girls' but fails 'players'.

• S is inside the square only — satisfies 'players' but fails 'girls'.

• R is inside the triangle, square, and circle — satisfies 'girls' and 'players' but fails 'not coach'.

• T is inside the square and circle only — satisfies 'players' but fails 'girls' and fails 'not coach'.

• U is inside the circle only — fails 'girls' and 'players' entirely.

Q is the only region inside both the triangle and the square while lying outside the circle, so it correctly represents the girls who are players but not coaches.