Sample spaces, events and complements

Develop reliable probability models through sample spaces, weighted outcomes, and complementary events. This precalculus practice set moves from identifying outcomes and checking a model to computing event probabilities and interpreting what a probability claim means. Questions distinguish equally likely outcomes from categories that have unequal weights. Single-select and multiselect items combine conceptual reasoning, fraction calculations, and error analysis, with detailed explanations that identify the correct sample space and the role of the complement. No conditional-probability or formal statistical-inference methods are required.