Independent solution

How to solve this Mutually Exclusive Events question

Setup

Setup

Use the additivity criterion for a finite collection of events.

Pr(UVW)=Pr(U)+Pr(V)+Pr(W)\Pr(U\cup V\cup W)=\Pr(U)+\Pr(V)+\Pr(W)
when U,V,W are pairwise disjoint\text{when }U,V,W\text{ are pairwise disjoint}

Model

Model

Check the proposed events A, B, and E two at a time using their year-specific requirements.

AB=A\cap B=\varnothing
AE=A\cap E=\varnothing
BE=B\cap E=\varnothing

Compute

Compute

Each intersection is impossible: A excludes any second- or third-year theft, while B and E impose contradictory second-year states.

Pr(ABE)=Pr(A)+Pr(B)+Pr(E)\Pr(A\cup B\cup E)=\Pr(A)+\Pr(B)+\Pr(E)

Answer

Answer

The additive triple is A, B, and E.

A,B,E(A)\boxed{A,B,E\quad\text{(A)}}