fila <- c(rep("VACANZA",15),rep("LAVORO",25))
prove <- 100000
num <- 0; den <- 0
for (i in 1:prove)
{
    out <- sample(fila,size=2,replace=FALSE)
    if (out[1]=="LAVORO") {
       den <- den + 1
       if (out[2]=="VACANZA") num <- num+1
    }
}

cat(num,den,num/den,"\n")