Incompetent = Acolyte

Nice and simple one.

In a two-child family, one child is a boy. What is the probability that
the other child is a girl?

Mark

I am, at once, tempted to jump in and say 50/50 and to stop. Lucky
I did. I'm afraid I can only be sure of myself on this one by listing
the possibilities.

girl/girl
boy/boy
boy/girl
girl/boy

This indiciates, in my less than certain opinion, that the probability is
2 in 3 or, as the bookies would have it, 2-1 on!

It seems a little unintuitive, but please tell me I'm right!!

-Chrismo

496, and as my friend richjohnson pointed out, after that comes
8128. These are the perfect numbers, they are the sums of their non-
identical divisors. 1 and 2 and 3 all divide evenly into 6, 1+2+3=6.

Bennett

Very true. Any ideas on why Pythagoras was so excited by these first
two numbers? Not just because of the divisors property but by
something else.

Clue: At the time he believed that 6 and 28 were the only numbers to
have this divisors property.


Mark

I studied Maths at Peterhouse, Cambridge but it was a good ten years
ago. I guess you're going to have a fantastic time. That said maybe
my time was so good because I was not very good at turning up for
lectures.

Let me know if they still play backgammon in the Pure Maths
Department.

Best of luck,

John.

Originally posted by T1000

The Maths you'll do at uni will be like familiarising yourself with Da
Vinci's Last Supper, whereas the Maths you'll have done at A-Level is
more like colouring by numbers. You'll just find it better. Better in the
way that great works of Literature are more interesting than the
dictionary.

Steer clear of Statistics (it just aint Maths). Embra ...[text shortened]...
6, 28, ...........? And why was Pythagoras obsessed with the first two
numbers?

Acolyte,

How is it going there at Cambridge? Are you leaning towards pure and/or applied maths?

Let me know if you bump into a lecturer called Dr. Leader.

John.

I think Acolyte might know Dr. Leader, because he told me about him.