This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune,[e] and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons in the Solar System, Triton has a retrograde orbit, indicating that it was captured rather than forming in place; it was probably once a dwarf planet in the Kuiper belt. It is close enough to Neptune to be locked into a synchronous rotation, and it is slowly spiralling inward because of tidal acceleration. It will eventually be torn apart, in about 3.6 billion years, when it reaches the Roche limit. In 1989, Triton was the coldest object that had yet been measured in the Solar System, with estimated temperatures of 38 K (−235 °C).
What planet has 13 moons?

Passage: During the early 20th century, northerners were attracted to the city, and Miami prospered during the 1920s with an increase in population and infrastructure. The legacy of Jim Crow was embedded in these developments. Miami's chief of police, H. Leslie Quigg, did not hide the fact that he, like many other white Miami police officers, was a member of the Ku Klux Klan. Unsurprisingly, these officers enforced social codes far beyond the written law. Quigg, for example, "personally and publicly beat a colored bellboy to death for speaking directly to a white woman."
Who was a unnotable chief of the Miami police?

Passage: The foundation of Northwestern University is traceable to a meeting on May 31, 1850 of nine prominent Chicago businessmen, Methodist leaders and attorneys who had formed the idea of establishing a university to serve what had once been known as the Northwest Territory. On January 28, 1851, the Illinois General Assembly granted a charter to the Trustees of the North-Western University, making it the first chartered university in Illinois. The school's nine founders, all of whom were Methodists (three of them ministers), knelt in prayer and worship before launching their first organizational meeting. Although they affiliated the university with the Methodist Episcopal Church, they were committed to non-sectarian admissions, believing that Northwestern should serve all people in the newly developing territory.

How many sellers did Northwestern University have?