# brain sizes: Einstein's and women's

Jet thatjetnospam at yahoo.com
Fri Jul 19 01:19:37 EST 2002

```
Parse Tree wrote:
>
> "mat" <mats_trash at hotmail.com> wrote in message
> > >
> > > If you're asked a question which has four multiple choice answers, and
> you
> > > haven't got a clue what the answer is, what is the probability of
> getting a
> > > correct answer?  Since you have once chance in four of getting the right
> > > answer, your probability is 0.25.  If you guess on two questions, your
> > > probability is .5, and three it's .75, and four, it's 1.0.
> >
> > So you are certain to get a correct answer if you guess on four
> > questions?  and you claim to understand probability?!
> >
> > P(one questions correct given 4 choices and if guessing) = 0.25
> > P(two questions correct) = 0.25 x 0.25 = 0.0625
> > P(three questions correct) = 0.25 x 0.25 x 0.25 = 0.015625
> > .
> > .
> > .
> > P(n questions correct) = 0.25^n
>
> Actually, he was talking about getting only one correct, as far as I can
> tell.  He's still wrong though.

He came to the conclusion that a negative number of people go the answer
right without guessing. I kid you not!

J

```