There must have been ten boys and twenty girls. The number of bows girl to girl was therefore 380, of boy to boy 90, of girl with boy 400, and of boys and girls to teacher 30, making together 900, as stated. It will be remembered that it was not said that the teacher himself returned the bows of any child.
98.--ACADEMIC COURTESIES.
From Amusements in Mathematics by Henry Ernest Dudeney.
