The problem: Answer a question about this article:
According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's demand for electricity by 2060 – and half of all energy needs – with wind, hydropower and biomass plants supplying much of the remaining generation". "Photovoltaic and concentrated solar power together can become the major source of electricity".
Photovoltaic and solar-thermal plants may meet most of the world's demand for electricity by what year?
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The answer: 2060


The problem: Answer a question about this article:
The Sumerians developed a complex system of metrology c. 4000 BC. This advanced metrology resulted in the creation of arithmetic, geometry, and algebra. From c. 2600 BC onwards, the Sumerians wrote multiplication tables on clay tablets and dealt with geometrical exercises and division problems. The earliest traces of the Babylonian numerals also date back to this period. The period c. 2700 – 2300 BC saw the first appearance of the abacus, and a table of successive columns which delimited the successive orders of magnitude of their sexagesimal number system. The Sumerians were the first to use a place value numeral system. There is also anecdotal evidence the Sumerians may have used a type of slide rule in astronomical calculations. They were the first to find the area of a triangle and the volume of a cube.
Where did the Sumerians put their multiplication tables?
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The answer: on clay tablets


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From outside the United Kingdom and the United States, the Canadian trio Rush released three distinctively hard rock albums in 1974–75 (Rush, Fly by Night and Caress of Steel) before moving toward a more progressive sound with the 1976 album 2112. The Irish band Thin Lizzy, which had formed in the late 1960s, made their most substantial commercial breakthrough in 1976 with the hard rock album Jailbreak and their worldwide hit "The Boys Are Back in Town", which reached number 8 in the UK and number 12 in the US. Their style, consisting of two duelling guitarists often playing leads in harmony, proved itself to be a large influence on later bands. They reached their commercial, and arguably their artistic peak with Black Rose: A Rock Legend (1979). The arrival of Scorpions from Germany marked the geographical expansion of the subgenre. Australian-formed AC/DC, with a stripped back, riff heavy and abrasive style that also appealed to the punk generation, began to gain international attention from 1976, culminating in the release of their multi-platinum albums Let There Be Rock (1977) and Highway to Hell (1979). Also influenced by a punk ethos were heavy metal bands like Motörhead, while Judas Priest abandoned the remaining elements of the blues in their music, further differentiating the hard rock and heavy metal styles and helping to create the New Wave of British Heavy Metal which was pursued by bands like Iron Maiden, Saxon and Venom.
What nationality was Thin Lizzy?
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The answer: Irish


The problem: Answer a question about this article:
Korolev's lunar landing program was designated N1/L3, for its N1 superbooster and a more advanced Soyuz 7K-L3 spacecraft, also known as the lunar orbital module ("Lunniy Orbitalny Korabl", LOK), with a crew of two. A separate lunar lander ("Lunniy Korabl", LK), would carry a single cosmonaut to the lunar surface.
The "Lunniy Korabl" or "LK" would carry how many people?
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The answer:
N1