Posts Celebrating Abers Birthdays Today Prompted This.

[sandyRoe]

If you went into a room containing 30 people what are the chances that at least one of them would have the same dob(the 12th for example)as yourself? I'd guess the odds would be quite low.

[wolf63]

This is a long explanation

[sandyRoe]

Ta, wolf63,
I'll have a look at that later.

[wolf63]

Your day, did it go well?

I have done sweet FA since my late lunch. I am now going for a snooze. It is piddling down outside.

[sandyRoe]

Twas a nice quiet day. Friends brought me an Xmas dinner about 4 so I'm full and ready for a nap.

[The Builder]

Wolfie's post gives all the gen Sandy. It's a known mathematical problem also known as the Birthday Paradox.
It's rather counter-intuitive. The answer is much much higher than you would imagine.

I looked it up for you.
For 30 people it's 70.6% chance. Hard to believe isn't it?

[sunny-dave]

Mr Builder - the paradox applies to *any* two of the group sharing a birthday - once you specify one person the odds become much simpler (and much worse).

[The Builder]

Professor Dave has it right.
I missed that Sandy called for a match with himself.

.......... back to the drawing board :o(((

[ZebuSanctuary]

// would have the same dob //

Take note, the probability only involves date and month. Not year born.

[ToraToraTora]

Nescio, don't come on here with your fancy maths! :) Many find that sort of thing offensive you know!

[ToraToraTora]

oops wrong post