if only one of them must say it correctly then it would be the last one to speak who would definitely get it right as he would have heard the others give their guesses and if it gets to him without anyone guessing correctly then he would know that all of the other guesses were wrong so he just has to tally up the opposite answers and say what colour his cap is based on that.
if only one of them must say it correctly then it would be the last one to speak who would definitely get it right as he would have heard the others give their guesses and if it gets to him without anyone guessing correctly then he would know that all of the other guesses were wrong so he just has to tally up the opposite answers and say what colour his cap is based on that.