times <- function(n) { dice <- as.integer(runif(n,1,21)) hit <- sum(ifelse(dice<5,1,0)) return(hit)} a <- c(4,10,20,50) layout(matrix(1:4,nr=2)) for (i in 1:4) { y <- 1:1000 for (k in 1:1000) { y[k] <- times(a[i]) } barplot(table(y),main=paste("n=",a[i])) }