4 ms·

Of course there's always the chance that there are multiple winners which affects either it's expected positive roi

bryanlarsen 4y ago
That is in the article, which mentions there's a 50% chance you're going to share the prize. So let's do the math. 35 cents go to non-jackpot prizes, so the ROI on that is 35 cents, leaving 1.65 for the jackpot. ROI on the jackpot is $1B / 400M odds. That's $2.50 shared amongst the winners. 50% of that is single winner, 50% is shared so $1.25 + $1.25 / 2 = $1.875. $1.875 is greater than 1.65, so the ROI for this lottery is slightly positive. (I don't have the numbers on odds of 3 or more sharing, so the ROI is actually slightly less than $1.875, but it won't be much of a reduction).
- 8n4vidtmkvmk 4y ago
  Article also said only 75 cents go to the jackpot. the rest goes to the government
  - bryanlarsen 4y ago
    The jackpot accumulates. It grew so high because there are many weeks worth of 75 cents. It's an average. Most weeks 0 cents goes to the jackpot because nobody wins, so on the weeks somebody wins, it's often significantly more than 75 cents. This is obvious because they're selling $400 million worth of tickets to a $1B jackpot.
    - hdjrudni 4y ago
      > The jackpot accumulates. It grew so high because there are many weeks worth of 75 cents. It's an average. Most weeks 0 cents goes to the jackpot because nobody wins, so on the weeks somebody wins, it's often significantly more than 75 cents. This sentence does not compute. If nobody wins for a week then however many tickets that were sold times 75 cents get added to the jackpot. If somebody wins, the jackpot is reset to $0. > This is obvious because they're selling $400 million worth of tickets to a $1B jackpot. $400M this week? Because they should have sold about 1.33 billion $2 tickets without a winner to reach a $1B jackpot, however many weeks that takes.
      - bryanlarsen 4y ago
        But I'm not buying tickets on the weeks with low jackpots, just the weeks with billion dollar ones.

That is in the article, which mentions there's a 50% chance you're going to share the prize. So let's do the math. 35 cents go to non-jackpot prizes, so the ROI on that is 35 cents, leaving 1.65 for the jackpot. ROI on the jackpot is $1B / 400M odds. That's $2.50 shared amongst the winners. 50% of that is single winner, 50% is shared so $1.25 + $1.25 / 2 = $1.875. $1.875 is greater than 1.65, so the ROI for this lottery is slightly positive. (I don't have the numbers on odds of 3 or more sharing, so the ROI is actually slightly less than $1.875, but it won't be much of a reduction).

8n4vidtmkvmk 4y ago
Article also said only 75 cents go to the jackpot. the rest goes to the government
- bryanlarsen 4y ago
  The jackpot accumulates. It grew so high because there are many weeks worth of 75 cents. It's an average. Most weeks 0 cents goes to the jackpot because nobody wins, so on the weeks somebody wins, it's often significantly more than 75 cents. This is obvious because they're selling $400 million worth of tickets to a $1B jackpot.
  - hdjrudni 4y ago
    > The jackpot accumulates. It grew so high because there are many weeks worth of 75 cents. It's an average. Most weeks 0 cents goes to the jackpot because nobody wins, so on the weeks somebody wins, it's often significantly more than 75 cents. This sentence does not compute. If nobody wins for a week then however many tickets that were sold times 75 cents get added to the jackpot. If somebody wins, the jackpot is reset to $0. > This is obvious because they're selling $400 million worth of tickets to a $1B jackpot. $400M this week? Because they should have sold about 1.33 billion $2 tickets without a winner to reach a $1B jackpot, however many weeks that takes.
    - bryanlarsen 4y ago
      But I'm not buying tickets on the weeks with low jackpots, just the weeks with billion dollar ones.