3: The Law of OR

In somewhat shorter form, let’s call the first event E1 and the second event
E2. In this case E1 would be winning the washer-dryer, E2 would be winning the toaster. And
let’s abbreviate “the probability of E1” to simply P(E1). Then we
can say:

P(E1or E2) = P(E1) + P(E2)

This looks a lot more official and impressive, but remember that the basic
idea is, add the chances together if you want to know the probability of one
thing or another thing.