Three business students – an accounting major a finance major and a managemnet major were traveling through Wisconsin when they saw a black cow through the window of the train. Aha says the managemnet major I see that Wisconsin cows are black. Hmm says the a finance major You mean that some Wisconsin cows are black. No says the accounting major All we know is that there is at least one cow in Wisconsin, and that at least one side of that one cow is black. 😀