Problem: One of the Han's greatest mathematical advancements was the world's first use of negative numbers. Negative numbers first appeared in the Nine Chapters on the Mathematical Art as black counting rods, where positive numbers were represented by red counting rods. Negative numbers are used in the Bakhshali manuscript of ancient India, but its exact date of compilation is unknown. Negative numbers were also used by the Greek mathematician Diophantus in about 275 AD, but were not widely accepted in Europe until the 16th century AD.
What were positive numbers portayed as in the treatise of the Nine Chapters on the Mathematical Art?
The answer is the following: red counting rods

Problem: In mid-1969, Idris travelled abroad to spend the summer in Turkey and Greece. Gaddafi's Free Officers recognized this as their chance to overthrow the monarchy, initiating "Operation Jerusalem". On 1 September, they occupied airports, police depots, radio stations and government offices in Tripoli and Benghazi. Gaddafi took control of the Berka barracks in Benghazi, while Omar Meheisha occupied Tripoli barracks and Jalloud seized the city's anti-aircraft batteries. Khweldi Hameidi was sent to arrest crown prince Sayyid Hasan ar-Rida al-Mahdi as-Sanussi, and force him to relinquish his claim to the throne. They met no serious resistance, and wielded little violence against the monarchists.
What revolutionary leader took control of the anti-aircraft equipment in Tripoli?
The answer is the following: Jalloud

Problem: In 1790, the first federal population census was taken in the United States. Enumerators were instructed to classify free residents as white or "other." Only the heads of households were identified by name in the federal census until 1850. Native Americans were included among "Other;" in later censuses, they were included as "Free people of color" if they were not living on Indian reservations. Slaves were counted separately from free persons in all the censuses until the Civil War and end of slavery. In later censuses, people of African descent were classified by appearance as mulatto (which recognized visible European ancestry in addition to African) or black.
When was the first US federal population census taken?
The answer is the following: In 1790, the first federal population census was taken in the United States

Problem: During the 2009–10 school year, there were a total of 10,979 pupils attending classes in Bern. There were 89 kindergarten classes with a total of 1,641 pupils in the municipality. Of the kindergarten pupils, 32.4% were permanent or temporary residents of Switzerland (not citizens) and 40.2% have a different mother language than the classroom language. The municipality had 266 primary classes and 5,040 pupils. Of the primary pupils, 30.1% were permanent or temporary residents of Switzerland (not citizens) and 35.7% have a different mother language than the classroom language. During the same year, there were 151 lower secondary classes with a total of 2,581 pupils. There were 28.7% who were permanent or temporary residents of Switzerland (not citizens) and 32.7% have a different mother language than the classroom language.
How many students were attending school during the 2009-2010 school year?
The answer is the following:
10,979