this post was submitted on 21 Jan 2024
62 points (83.0% liked)

[Outdated, please look at pinned post] Casual Conversation

6590 readers
1 users here now

Share a story, ask a question, or start a conversation about (almost) anything you desire. Maybe you'll make some friends in the process.


RULES

Related discussion-focused communities

founded 1 year ago
MODERATORS
 

(or the equivalent of your local currency if your country doesn't use US dollars.)

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 9 points 10 months ago* (last edited 10 months ago)

A mega sena (popular lottery ticket in Brazil) costs five reals if you fill it with six numbers. So I'd certainly pick the 5 reals bill, as the expected value per real is always smaller.

The picture changes if the ticket was filled with more numbers; if you hit any six then you get the jackpot, and it's accordingly more expensive (seven numbers for R$35,00; eight for R$140,00). For those I'd need to do the maths, but there are complicating factors:

  • if multiple people hit the jackpot, the prize gets split
  • there's a secondary prize if you hit five numbers, and a tertiary one if you hit four
  • the jackpot varies quite a bit from one draw to another, as it accumulates if nobody hit it in the previous draw

To simplify it: let's say that only the primary prize counts, it's around 30 million reals (typical value), and that your odds are one in 50 million. Then the expected value becomes:

  • with 6 numbers: R$30M/50M = R$0,60
  • with 7 numbers: 7*(R$0,60) = R$4,20
  • with 8 numbers: 8*(R$4,20) = R$33,60

The five reals bill is still more valuable than a mega sena ticket with seven numbers, even if it costs R$35. But if it was eight, I'd pick the ticket.