Solution

(related to Problem: Academic Courtesies)

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.


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References

Project Gutenberg

  1. Dudeney, H. E.: "Amusements in Mathematics", The Authors' Club, 1917

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