channelflow.org

% You have a sack of nine balls, three each red, green, blue.
% If you draw two balls out of the sack, what's the chance they are
% both green?

Ntrials = 1000;   % number of trials
r = 0;
g = 1;
b = 2;
sack = [r r r g g g b b b]; 
Nballs  = length(sack);
count = 0;

for n=1:Ntrials
  draw  = sack(randperm(9));
  count = count + (sum(draw(1:2) == [g g]) == 2);
  
  % If Matlab were a real programming language, it would accept
  % count = count + (sum(sack(randperm(9))(1:2) == [g g]) == 2);
end

fprintf('The prob of choosing two green balls first is %f\n', count/Ntrials);