Monty Hodlonaut

montyhodlonaut.js

BOXES = [[ '₿',  '₿'], // Box A
         [ '₿', '💩'], // Box B
         ['💩', '💩']] // Box C

var count = 0, success = 0;

while(count <= 1_000_000) {

  // You choose a box at random
  var drawbox = Math.floor(Math.random() * 3); 
  var box = BOXES[drawbox];
  
  // and withdraw one coin at random
  var drawcoin = Math.floor(Math.random() * 2);
  var coin = box[drawcoin];

  // if it happens to be a bitcoin
  if (coin == '₿') {

    // the next coin drawn from the same box
    var nextcoin = box[1 - drawcoin];

    // what is the chance of it also being a bitcoin?
    if (nextcoin == '₿') success++;
    
    count ++;
  }
}

var percentage = (success / count) * 100;
console.log(`Odds of drawing Bitcoin: ${percentage.toFixed(2)}`)

https://twitter.com/hodlonaut/status/1523237743626788864

Three boxes with 2 coins each

Box a: 2 bitcoins
Box b: 1 bitcoin, 1 shitcoin
Box c: 2 shitcoins

You choose a box at random and withdraw one coin at random

Question: if it happens to be a bitcoin, what is the chance of the next coin drawn from the same box also being a bitcoin?