The sample space is the set of all possible outcomes. Since the marbles are replaced, the outcome of the first draw does not affect the second draw. The possible marbles are P1, P2, O, and R. The sample space is formed by pairing each marble with every other marble, including itself.
The sample space is:
- (P1, P1), (P1, P2), (P1, O), (P1, R)
- (P2, P1), (P2, P2), (P2, O), (P2, R)
- (O, P1), (O, P2), (O, O), (O, R)
- (R, P1), (R, P2), (R, O), (R, R)