Question

Four swimmers, Daniela, Camille, Brennan, and Amy, compete on a relay team. For the first race of the year, Daniela begins the relay. The other three swimmers can swim in any order. The sample space, S, for the event is shown below.

S = {CBA, CAB, BAC, BCA, ACB, ABC}

After the first race, it is determined that Camille is a strong finisher and should be the final swimmer in the race.

What subset, A, of the sample space represents the complement of the event in which Camille is the final swimmer?

A = {CBA, CAB, BCA, ACB}
A = {ABC, BAC}
A = {CBA, CAB, BAC, BCA, ACB, ABC}
A = {AB, BA}

Answer 1

Camille is the final swimmer in the sequences with last letter C: {BAC, ABC}. The complement is the other four sequences:
A = {CBA, CAB, BCA, ACB}.