Liber Aboali Abincine de Anima in arte Alchemiae was the most influential, having influenced later medieval chemists and alchemists such as Vincent of Beauvais. However Anawati argues (following Ruska) that the de Anima is a fake by a Spanish author. Similarly the Declaratio is believed not to be actually by Avicenna. The third work (The Book of Minerals) is agreed to be Avicenna's writing, adapted from the Kitab al-Shifa (Book of the Remedy). Ibn Sina classified minerals into stones, fusible substances, sulfurs, and salts, building on the ideas of Aristotle and Jabir. The epistola de Re recta is somewhat less sceptical of alchemy; Anawati argues that it is by Avicenna, but written earlier in his career when he had not yet firmly decided that transmutation was impossible.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is definitely seen as being written by Avicenna?
Ah, so.. The Book of Minerals

Greece attracts more than 16 million tourists each year, thus contributing 18.2% to the nation's GDP in 2008 according to an OECD report. The same survey showed that the average tourist expenditure while in Greece was $1,073, ranking Greece 10th in the world. The number of jobs directly or indirectly related to the tourism sector were 840,000 in 2008 and represented 19% of the country's total labor force. In 2009, Greece welcomed over 19.3 million tourists, a major increase from the 17.7 million tourists the country welcomed in 2008.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many jobs in 2008 in Greece were somehow related to the tourism industry?
Ah, so.. 840,000

Chopin's relations with Sand were soured in 1846 by problems involving her daughter Solange and Solange's fiancé, the young fortune-hunting sculptor Auguste Clésinger. The composer frequently took Solange's side in quarrels with her mother; he also faced jealousy from Sand's son Maurice. Chopin was utterly indifferent to Sand's radical political pursuits, while Sand looked on his society friends with disdain. As the composer's illness progressed, Sand had become less of a lover and more of a nurse to Chopin, whom she called her "third child". In letters to third parties, she vented her impatience, referring to him as a "child," a "little angel", a "sufferer" and a "beloved little corpse." In 1847 Sand published her novel Lucrezia Floriani, whose main characters—a rich actress and a prince in weak health—could be interpreted as Sand and Chopin; the story was uncomplimentary to Chopin, who could not have missed the allusions as he helped Sand correct the printer's galleys. In 1847 he did not visit Nohant, and he quietly ended their ten-year relationship following an angry correspondence which, in Sand's words, made "a strange conclusion to nine years of exclusive friendship." The two would never meet again.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did Chopin end his relationship with Sand?
Ah, so..
1847