Wikipedia:Reference desk/Archives/Mathematics/2016 July 12

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July 12

my "bold" edit regarding Cantor's Diagonal Lemma

I made an edit here: Cantor's diagonal argument, oldid=729475472 diff=prev

I think I'm right but not 100% sure...see the article talk section too..(I think this is easier than me explaining it all)..68.48.241.158 (talk) 13:23, 12 July 2016 (UTC)

Yes that's fine thanks. Dmcq (talk) 14:59, 12 July 2016 (UTC)

You agree with the edit or you're okay with how I posed the question?68.48.241.158 (talk) 15:09, 12 July 2016 (UTC)

In case people don't want to go looking, question is basically this: is what is known as Cantor's Diagonal lemma technically used in any way at all in the formal demonstration of what is known as Russell's paradox/antinomy..??(I think it is not)68.48.241.158 (talk) 15:42, 12 July 2016 (UTC)

There's a new thread with discussion on the article's talkpage if people want to just go there instead and explain/weigh-in as it will then answer my question/possibly improve the encyclopedia at the same time... (as no one has been here yet anyway)..68.48.241.158 (talk) 18:05, 12 July 2016 (UTC)

What is the expected value of mega sena loterry?

What is the expected value of mega sena loterry?
Mega sena with a prize of 20000000 brazillian reals would work like this:
People select numbers between 1 and 60, they must pick 6 different numbers and they must be different, their order is irrelevant.To "play" they must pay 3.5 brazillian dollars.
Then at some point of the month, mega sena pick 6 different numbers between 1 and 60, again order doenst matter
If you guessed right the 6 numbers you get 7000000 brazillian reals.
If you guessed right 5 numbers but didnt guessed right 6, you get 3800000 dollars.
If you guessed right 4 numbers but didnt guessed right 5 or 6, you get 3800000 dollars.
Under those specific conditions what is the expected value of mega sena 201.79.78.164 (talk) 20:23, 12 July 2016 (UTC)

The number of ways picking 6 numbers out of 60 is ${\binom {60}{6}}=50063860$

The number of ways picking 6 correct numbers is ${\binom {6}{6}}=1$

The number of ways picking 5 correct numbers and 1 incorrect number is ${\binom {6}{5}}{\binom {54}{1}}=324$

The number of ways picking 4 correct numbers and 2 incorrect numbers is ${\binom {6}{4}}{\binom {54}{2}}=21465$

The expected value is $(A+324B+21465C)/50063860$ where A, B and C are the price money. (Some prizes are in Brazillian Reals and some are in Dollars. Check the numbers and look the rate of change up yourself). Bo Jacoby (talk) 22:50, 12 July 2016 (UTC).

According to our article, the drawing is held twice per week, not once a month. Also, the total prize is based on ticket sales, so it changes from drawing to drawing. Furthermore, R$ 7000000 jackpot and the R$ 3800000 (it should read Reals) for 4 and 5 correct is split among the respective winners, so there's no way to get an expected value without knowing how many tickets were sold. But the total payout for the various types of drawings is fixed at 46% of ticket sales, so on average the expected payout for a R$3.5 ticket is R$ 3.6 × .46 = R$ 1.656. Income tax takes out some of the winnings so the actual expected payout is somewhat less. --RDBury (talk) 00:17, 13 July 2016 (UTC)