What does {B or D} mean in words?

A question for my statistics class dealing with probability, but I can't find it anywhere in the book or notes :/

?2011-06-19T19:06:51Z

Favorite Answer

it means:

either B is true (or has occured) or D is true (or has occured) or both.

this is the logical OR, in sets, it refers to the union.