(This article was first published on

**Xi'an's Og » R**, and kindly contributed to R-bloggers)**H**ere is a quick-and-dirty solution to * Le Monde* puzzle posted a few days ago: the R code counts the number of winning tickets between 1 and N, and stops when there is a proportion of 10% of winning tickets.

#winning ticket win=function(n){ #decimal digits decomposition x=rep(0,4) x[4]=n%%10 m=(n-x[4])/10 x[3]=m%%10 m=(m-x[3])/10 x[2]=m%%10 m=(m-x[2])/10 x[1]=m%%10 tic=0 for (i in 1:3) tic=max(tic,(x[i]==1)*(x[(i+1):4]==3)) return(tic) } #number of winning tickets nwt=0 for (i in 1:9999){ nwt=nwt+win(i) if ((i>999)&&(10*nwt==i)) break()} #solution print(i)

**T**he (only) solution is therefore N=3500. (I am using this home-made decomposition of a number into its decimal digits, but there must be some function doing that in R already!)

Filed under: R, Statistics Tagged: Le Monde, mathematical puzzle, R

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