Would you take this Gamble?

Question

You are in the Pub and 10 people are present including you and a friend. Your friend makes you a wager that for every person you find that has the same birthday as you, you get £100 but for every person he finds that does not have the same birthday as you, he gets £10. Would you accept the wager and why?

Answer 1

what if you were there with all your brothers and sisters and you were part of a octuplet twin set?

then you would make £700 so as long as there is less than 70 people in the pub then it would be a good bet.

Answer 2

Don't take the bet!

In particular, don't take any notice of Bill and his birthday paradox.

He has got himself muddled. He would seem to have read your question incorrectly and simply assumed it is an example of the birthday paradox, which it ain't.

To clarify the point, the paradox deals with ANY two of those present sharing birthdays. Your question deals with those who share specifically with YOU, and you alone. Some of the others may share birthdays but so what? That doesn't help you - you still lose.

Answer 3

sure.    you find yourself you win a hundred.   your friend is a drunk so when he finds you, you are up 2 hundred.   then he says p**s off and stumbles away leaving 90 on the table...

Answer 4

I would definately take the bet! All what you got!

Answer 5

No I would not because you have a 1 in 365 chnace of winning a £100. He has a 364 chance of winning.

Answer 6

I assume that you know your friend's birthday is not the same as yours so there are only 8 unknowns. It's a no brainer. The expected value of success is 8 x 1/365 x £100 whereas the expected cost of failure is 8 x 364/365 x £10.

Incidentally the chances of ANY 2 people having the same birthday among 10 strangers present is 0.116944 which is between 1 chance in 8 and 1 in 9, more precisely 1 in 8.55.

Answer 7

No way, statistically one in 365 people will have the same birthday as you,the odds are loaded in his favour.

Answer 8

wow wrong answers by everyone

the odds of having the same birthday as someone else when there is 10 people is 11.7%.  so getting 10 to 1 odds is excellent since there is a great chance that at least 2 people will share a birthday

this is done by doing

1 - [(365*364*363*362*361*360*359*

358*357*356)/365^10]

this is known as the birthday paradox

the formula is for n people, use

p(n) = [365*364*363*......(365-n+1)]/365^n

that tells you the odds that nobody shares it

to find that odds that someone does, take 1 - that answer

to convert to a percent multiply by 100

TAKE THE BET!!!

Answer 9

Na but i am not really a gambler as I am to tight with money

Answer 10

I wouldn't because thee is only a 1 in 365 chance of getting someone with exactly the same b'day as yours.

There is  364 in 365 chances of someone not having the same b'day as you, resulting in paying out more often.

Answer 11

no because the outcome is going to more greater on his side because out of all the people there, what are the odds of you having the same birthday as another person, but if you have a birthday such as jan 1st or something then yes or another popular birthday it could workout but other than that i do not see it working out