Puzzles
Two men spot a flock of storks and work out the count through triples and thirds
In Alcuin's puzzle, two walkers see a flock of storks and try to guess how many there are. They reason: if there were three times as many storks, plus half of a third of that tripled number, plus two more that just arrived, the total would be exactly 100. How many storks were actually in the flock?
Reveal the answer
28. Three times 28 is 84; half of a third of 84 is 14; 84 plus 14 plus the 2 latecomers makes exactly 100. It's one of about 53 brainteasers in Alcuin's Propositiones ad Acuendos Juvenes ('Problems to Sharpen the Young'), written around 800 CE for Charlemagne's court, among the oldest surviving puzzle collections in the Western world.
— Alcuin of York, Propositiones ad Acuendos Juvenes — c. 800 CE