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: In the CFL, if the game is tied at the end of regulation play, then each team is given an equal number of chances to break the tie. A coin toss is held to determine which team will take possession first; the first team scrimmages the ball at the opponent's 35-yard line and advances through a series of downs until it scores or loses possession. If the team scores a touchdown, starting with the 2010 season, it is required to attempt a 2-point conversion. The other team then scrimmages the ball at the same 35-yard line and has the same opportunity to score. After the teams have completed their possessions, if one team is ahead, then it is declared the winner; otherwise, the two teams each get another chance to score, scrimmaging from the other 35-yard line. After this second round, if there is still no winner, during the regular season the game ends as a tie. In a playoff or championship game, the teams continue to attempt to score from alternating 35-yard lines, until one team is leading after both have had an equal number of possessions.

SOLUTION: After teams have completed their 2 point conversions, who is declared the winner?

PROBLEM: Passage: Terra preta (black earth), which is distributed over large areas in the Amazon forest, is now widely accepted as a product of indigenous soil management. The development of this fertile soil allowed agriculture and silviculture in the previously hostile environment; meaning that large portions of the Amazon rainforest are probably the result of centuries of human management, rather than naturally occurring as has previously been supposed. In the region of the Xingu tribe, remains of some of these large settlements in the middle of the Amazon forest were found in 2003 by Michael Heckenberger and colleagues of the University of Florida. Among those were evidence of roads, bridges and large plazas.

SOLUTION: Terra preta is distributor over a small area of what?

PROBLEM: Passage: The 2000 U.S. Census in the write-in response category had a code listing which standardizes the placement of various write-in responses for automatic placement within the framework of the U.S. Census's enumerated races. Whereas most responses can be distinguished as falling into one of the five enumerated races, there remains some write-in responses which fall into the "Mixture" heading which cannot be racially categorized. These include "Bi Racial, Combination, Everything, Many, Mixed, Multi National, Multiple, Several and Various".

SOLUTION:
What did the 1990 census have in the write-in response category?