Context and question: Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded the following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City, Utah. Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red.
Who was injured by a traffic light in Salt Lake City?
Answer: unanswerable
Context and question: In February 2016, over a hundred thousand people signed a petition in just twenty-four hours, calling for a boycott of Sony Music and all other Sony-affiliated businesses after rape allegations against music producer Dr. Luke were made by musical artist Kesha. Kesha asked a New York City Supreme Court to free her from her contract with Sony Music but the court denied the request, prompting widespread public and media response. 
Rape allegations were made against music producer Kesha against artist?
Answer: unanswerable
Context and question: The Scheinergrade (Sch.) system was devised by the German astronomer Julius Scheiner (1858–1913) in 1894 originally as a method of comparing the speeds of plates used for astronomical photography. Scheiner's system rated the speed of a plate by the least exposure to produce a visible darkening upon development. Speed was expressed in degrees Scheiner, originally ranging from 1° Sch. to 20° Sch., where an increment of 19° Sch. corresponded to a hundredfold increase in sensitivity, which meant that an increment of 3° Sch. came close to a doubling of sensitivity.
Approximately how many degrees indicate double the sensitivity? 
Answer:
an increment of 3° Sch