Eliza owns a firm that makes and sells two products, Product A and Product B$.$ Eliza believes the unit contribution margin from Product B is $$15,$ but is uncertain about the unit contribution margin from Product A$.$ She estimates that the unit contribution margin of Product A is either $$0$ or $$20,$ which each being equally likely. Both products are processed on a single machine, which has total capacity of $900$ hours. Each unit of Product A requires $5$ hours on the machine, while each unit of Product B requires $4$ hours on the machine. Both products also require safety testing, and there are a total of $900$ hours available for safety testing. Each unit of Product A requires $4$ hours of safety testing, while each unit of Product B requires $5$ hours of safety testing.

a$.$ Using Solver, what product mix will maximize total contribution margin?

Show me in excel.