Problem: As with the spoken languages, the ethnic group composition also remains a point of debate, mainly regarding the largest and second largest ethnic groups, the Persians and Azerbaijanis, due to the lack of Iranian state censuses based on ethnicity. The CIA's World Factbook has estimated that around 79% of the population of Iran are a diverse Indo-European ethno-linguistic group that comprise the speakers of Iranian languages, with Persians constituting 53% of the population, Gilaks and Mazanderanis 7%, Kurds 10%, Lurs 6%, and Balochs 2%. Peoples of the other ethnicities in Iran make up the remaining 22%, with Azerbaijanis constituting 16%, Arabs 2%, Turkmens and Turkic tribes 2%, and others 2% (such as Armenians, Talysh, Georgians, Circassians, Assyrians).
Ethnic minorities such as Azerbaijanis make up what percentage of Iran's population?
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Answer: 22%

Problem: In the United States, 25 Hz, a once-common industrial power frequency is used on Amtrak's 25 Hz traction power system at 12 kV on the Northeast Corridor between Washington, D.C. and New York City and on the Keystone Corridor between Harrisburg, Pennsylvania and Philadelphia. SEPTA's 25 Hz traction power system uses the same 12 kV voltage on the catenary in Northeast Philadelphia. This allows for the trains to operate on both the Amtrak and SEPTA power systems. Apart from having an identical catenary voltage, the power distribution systems of Amtrak and SEPTA are very different. The Amtrak power distribution system has a 138 kV transmission network that provides power to substations which then transform the voltage to 12 kV to feed the catenary system. The SEPTA power distribution system uses a 2:1 ratio autotransformer system, with the catenary fed at 12 kV and a return feeder wire fed at 24 kV. The New York, New Haven and Hartford Railroad used an 11 kV system between New York City and New Haven, Connecticut which was converted to 12.5 kV 60 Hz in 1987.
The Keystone Corridor connects Washington, D.C. and what city?
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Answer: unanswerable

Problem: Comcast is sometimes described as a family business. Brian L. Roberts, Chairman, President, and CEO of Comcast, is son of co-founder Ralph Roberts. Roberts owns or controls just over 1% of all Comcast shares but all of the Class B supervoting shares, which gives him an "undilutable 33% voting power over the company". Legal expert Susan P. Crawford has said this gives him "effective control over its [Comcast's] every step". In 2010, he was one of the highest-paid executives in the United States, with total compensation of about $31 million.
Who is Brian L. Robert's son?
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Answer:
unanswerable