Niccolò Tartaglia was an Italian mathematician, engineer and bookkeeper, living in the 16th century in the Republic of Venice. Tartaglia published many books, including his "General Trattato di Numeri", an acclaimed compilation of the mathematics known at his time. Among many other problems, the Trattato contained the following mathematical puzzle:
A dishonest servant takes out three pints of wine from a barrel and replaces them with the same amount of water. He repeats this theft another two times, removing altogether nine pints and replacing them with water. As a result of this swindle, the diluted wine remaining in the barrel lost half of its former strength.
How much wine was in the barrel before the thievery began?
(Note: Tartaglia is also famous for his solution of the cubic equation. The cubic equation that is implicit in this puzzle, however, is of a simple form that could be solved already before Tartaglia's work.)