Churn 2024-09-01

gistfile1.txt

#You have 3 urns, each containing 100 balls.
#In the first two, 99 of the balls are red and the last is green. 
#In the third urn, all 100 balls are red. 
#You choose one of the urns at random and remove 99 randomly chosen balls from it; they’re all red. 
#The last is probably?


library(tidyverse)

pick_ball <- function(){
    
    churn1 <- c(rep(1,99),0)
    
    churn2 <- c(rep(1,99),0)
    
    churn3 <- rep(1,100)
    
churn <- sample(
    list(churn1=churn1,churn2=churn2,churn3=churn3)
    ,1
    ) |> 
    pluck(1)

picks <- sample(churn,100,replace = FALSE)

if(all(picks[1:99]==1)){
    
    out <- picks[100]
    
    return(out)
    }
}

out <- replicate(1000000,pick_ball()) |> 
    purrr::flatten_dbl()

out |>  mean()