It was encouraging to receive some letters following the article, in the 1969 December Gazette (Vol. LIII, No. 386), entitled “Playing with Probability”. Most of the letters made reference to the use of “a steam hammer to crack a walnut”. The purpose of the article was to review the teaching of probability at three levels in a secondary school, and since stochastic matrices are to be found in the further mathematics of the School Mathematics Project it seemed appropriate to give an example which used them. The fact that the particular example chosen could be answered in one line does not detract from the interest of the method used in the article—although, of course, as mathematicians we are always looking for elegance.