TASK DEFINITION: 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.
PROBLEM: Passage: The city's municipal government was dominated by about 1215 merchant families, whose wealth came from overseas trade with continental Europe in particular the export of wool and hides and the import of salt, iron and wine. The medieval population of Cork was about 2,100 people. It suffered a severe blow in 1349 when almost half the townspeople died of plague when the Black Death arrived in the town. In 1491, Cork played a part in the English Wars of the Roses when Perkin Warbeck a pretender to the English throne, landed in the city and tried to recruit support for a plot to overthrow Henry VII of England. The then mayor of Cork and several important citizens went with Warbeck to England but when the rebellion collapsed they were all captured and executed. The title of Mayor of Cork was established by royal charter in 1318, and the title was changed to Lord Mayor in 1900 following the knighthood of the incumbent Mayor by Queen Victoria on her Royal visit to the city.

SOLUTION: How many aristocratic families dominated the government?

PROBLEM: Passage: The United States Mint produces Proof Sets specifically for collectors and speculators. Silver Proofs tend to be the standard designs but with the dime, quarter, and half dollar containing 90% silver. Starting in 1983 and ending in 1997, the Mint also produced proof sets containing the year's commemorative coins alongside the regular coins. Another type of proof set is the Presidential Dollar Proof Set where four special $1 coins are minted each year featuring a president. Because of budget constraints and increasing stockpiles of these relatively unpopular coins, the production of new Presidential dollar coins for circulation was suspended on December 13, 2011, by U.S. Treasury Secretary Timothy F. Geithner. Future minting of such coins will be made solely for collectors.

SOLUTION: What is specifically produced for budget constraints?

PROBLEM: Passage: By the late 19th century scientists realized that air could be liquefied, and its components isolated, by compressing and cooling it. Using a cascade method, Swiss chemist and physicist Raoul Pierre Pictet evaporated liquid sulfur dioxide in order to liquefy carbon dioxide, which in turn was evaporated to cool oxygen gas enough to liquefy it. He sent a telegram on December 22, 1877 to the French Academy of Sciences in Paris announcing his discovery of liquid oxygen. Just two days later, French physicist Louis Paul Cailletet announced his own method of liquefying molecular oxygen. Only a few drops of the liquid were produced in either case so no meaningful analysis could be conducted. Oxygen was liquified in stable state for the first time on March 29, 1883 by Polish scientists from Jagiellonian University, Zygmunt Wroblewski and Karol Olszewski.

SOLUTION:
What were Pierre Raoul Pictet's professions?