Probabilistic Thinking $2$: Loads and Reactions

Consider a simply supported beam $AB$ with two concentrated loads $P_1$ and $P_2$ as shown.

The possible values for $P_1($in kips$)$ are $4,5,$ and $6.$

The possible values for $P_2($in kips$)$ are $3,$ and $4.$

What is the chance that the reaction at $A$ is between $4$ kips and $5$ kips.