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 use of alloys by humans started with the use of meteoric iron, a naturally occurring alloy of nickel and iron. It is the main constituent of iron meteorites which occasionally fall down on Earth from outer space. As no metallurgic processes were used to separate iron from nickel, the alloy was used as it was. Meteoric iron could be forged from a red heat to make objects such as tools, weapons, and nails. In many cultures it was shaped by cold hammering into knives and arrowheads. They were often used as anvils. Meteoric iron was very rare and valuable, and difficult for ancient people to work.

SOLUTION: What was the first man-made alloy used by humans?

PROBLEM: Passage: Ann Arbor is a major scene of college sports, most notably at the University of Michigan, a member of the Big Ten Conference. Several well-known college sports facilities exist in the city, including Michigan Stadium, the largest American football stadium in the world. The stadium was completed in 1927 and cost more than $950,000 to build. It has a 109,901 seating capacity after multiple renovations were made. The stadium is colloquially known as "The Big House". Crisler Center and Yost Ice Arena play host to the school's basketball (both men's and women's) and ice hockey teams, respectively. Concordia University, a member of the NAIA, also fields sports teams.

SOLUTION: What stadium was completed in 1972?

PROBLEM: Passage: Since the late 18th century, Sanskrit has been transliterated using the Latin alphabet. The system most commonly used today is the IAST (International Alphabet of Sanskrit Transliteration), which has been the academic standard since 1888. ASCII-based transliteration schemes have also evolved because of difficulties representing Sanskrit characters in computer systems. These include Harvard-Kyoto and ITRANS, a transliteration scheme that is used widely on the Internet, especially in Usenet and in email, for considerations of speed of entry as well as rendering issues. With the wide availability of Unicode-aware web browsers, IAST has become common online. It is also possible to type using an alphanumeric keyboard and transliterate to Devanagari using software like Mac OS X's international support.

SOLUTION:
What Greek alphabet has been transliterated since the 18th century?