Question

Determine the sample space for the experiment.
Three marbles are selected from marbles labeled A through D where the marbles are not replaced and the order of selection does not matter.

Answer 1

The sample space is a set of all possible outcomes.
Since we are picking 3 marbles without replacement, and order does not count, there are only 4 possible outcomes, starting with:
Ω={(A,B,C), ...}