Article: 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.

Question: In what treatise did negative numbers first appear?
Ans: the Nine Chapters on the Mathematical Art

Article: On 14 June 1925, in a spontaneous reaction against Primo de Rivera's dictatorship, the crowd in the stadium jeered the Royal March. As a reprisal, the ground was closed for six months and Gamper was forced to relinquish the presidency of the club. This coincided with the transition to professional football, and, in 1926, the directors of Barcelona publicly claimed, for the first time, to operate a professional football club. On 3 July 1927, the club held a second testimonial match for Paulino Alcantara, against the Spanish national team. To kick off the match, local journalist and pilot Josep Canudas dropped the ball onto the pitch from his airplane. In 1928, victory in the Spanish Cup was celebrated with a poem titled "Oda a Platko", which was written by a member of the Generation of '27, Rafael Alberti, inspired by the heroic performance of the Barcelona goalkeeper, Franz Platko. On 23 June 1929, Barcelona won the inaugural Spanish League. A year after winning the championship, on 30 July 1930, Gamper committed suicide after a period of depression brought on by personal and financial problems.

Question: In what year did the directors of Barcelona first claim to operate a professional football club?
Ans: 1926

Article: An electrostatic motor is based on the attraction and repulsion of electric charge. Usually, electrostatic motors are the dual of conventional coil-based motors. They typically require a high-voltage power supply, although very small motors employ lower voltages. Conventional electric motors instead employ magnetic attraction and repulsion, and require high current at low voltages. In the 1750s, the first electrostatic motors were developed by Benjamin Franklin and Andrew Gordon. Today the electrostatic motor finds frequent use in micro-electro-mechanical systems (MEMS) where their drive voltages are below 100 volts, and where moving, charged plates are far easier to fabricate than coils and iron cores. Also, the molecular machinery which runs living cells is often based on linear and rotary electrostatic motors.[citation needed]

Question: What type of motor is based on the attraction and repulsion of electric charge?
Ans: electrostatic

Article: Encouraged by these successes, Nintendo soon turned its attention to the North American market. Nintendo entered into negotiations with Atari to release the Famicom under Atari's name as the name Nintendo Advanced Video Gaming System. The deal was set to be finalized and signed at the Summer Consumer Electronics Show in June 1983. However, Atari discovered at that show that its competitor Coleco was illegally demonstrating its Coleco Adam computer with Nintendo's Donkey Kong game. This violation of Atari's exclusive license with Nintendo to publish the game for its own computer systems delayed the implementation of Nintendo's game console marketing contract with Atari. Atari's CEO Ray Kassar was fired the next month, so the deal went nowhere, and Nintendo decided to market its system on its own.g["]

Question: What was the name of the fired Atari CEO?
Ans:
Ray Kassar