Once upon a time, the sultan baked a royal pie, filling it with all of the glorious and delicious fruits of his secret and sacred garden. While the pie was cooling, an assassin crept into the palace, cut the pie into twelve pieces, replacing all but one with inferior and poisonous pie slices, identical from the outside to the single original slice. Then the assassin fled before his knavery could be discovered. The sultan served the pie to the haseki sultan, who was an expert in algebra and daydreaming. As she was about to eat the pie, she thought, what if this wonderful pie were not whole? What if only one piece belonged to the original pie her beloved sultan had baked? And what if all the other pieces had been poisoned by a crafty assassin? What formula could she employ to solve the problem?