Super Duper Extra Hard Brainteaser
 

I'll open with a well know semi-easy one:

You know that a woman has exactly 2 children. You ask her if she has at least one girl, and she says yes. What's the probability that she has two girls?

Answer in white:

<font color="white"> 1/3 </font>

Now, suppose that 1% of all girls are named Sarah, and that if a mother had two girls that the mother would not name both of them Sarah

You know a woman has exactly 2 children, you ask her if she has a girl named Sarah, she says yes.

What are the chances she has two girls?

Re: Super Duper Extra Hard Brainteaser
 

I'm getting just under 1/5 but I could well be out.

Re: Super Duper Extra Hard Brainteaser
 

For a 140+ IQ you don't seem too confident.

Re: Super Duper Extra Hard Brainteaser
 

I am wrong.

Re: Super Duper Extra Hard Brainteaser
 

i'd say, 1/3

Re: Super Duper Extra Hard Brainteaser
 

I say 1/3 for both, assuming an equal distribution of boys and girls (that a woman is equally likely to have a boy as a girl, not 60/40 or 55/45 or whatever it is in reality).

Re: Super Duper Extra Hard Brainteaser
 

[ QUOTE ]
For a 140+ IQ you don't seem too confident.

[/ QUOTE ]

Should a person with 140+ IQ necessarily be confident?

Re: Super Duper Extra Hard Brainteaser
 

</font><blockquote><font class="small">In risposta di:</font><hr />
</font><blockquote><font class="small">In risposta di:</font><hr />
For a 140+ IQ you don't seem too confident.

[/ QUOTE ]

Should a person with 140+ IQ necessarily be confident?

[/ QUOTE ]

no

Re: Super Duper Extra Hard Brainteaser
 

Now I'm getting 199/399, but still not sure. Give me 5 mins.

Re: Super Duper Extra Hard Brainteaser
 

[ QUOTE ]
[ QUOTE ]
For a 140+ IQ you don't seem too confident.

[/ QUOTE ]

Should a person with 140+ IQ necessarily be confident?

[/ QUOTE ]

in his ability to figure out this xtra hard brain teaser?....yes!!