The problem: Answer a question about this article:
LEDs have been developed by Seoul Semiconductor that can operate on AC power without the need for a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficacy of this type of HP-LED is typically 40 lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named as 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design.
What is the efficacy of an AC powered HP-LED?
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The answer: 40 lm/W


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In early August 2008, Iowa Labour Commissioner David Neil announced that his department had found that Agriprocessors, a kosher meatpacking company in Postville which had recently been raided by Immigration and Customs Enforcement, had employed 57 minors, some as young as 14, in violation of state law prohibiting anyone under 18 from working in a meatpacking plant. Neil announced that he was turning the case over to the state Attorney General for prosecution, claiming that his department's inquiry had discovered "egregious violations of virtually every aspect of Iowa's child labour laws." Agriprocessors claimed that it was at a loss to understand the allegations. Agriprocessors' CEO went to trial on these charges in state court on 4 May 2010. After a five-week trial he was found not guilty of all 57 charges of child labour violations by the Black Hawk County District Court jury in Waterloo, Iowa, on 7 June 2010.
How many minors did Agriprocessors employ?
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The answer: 57


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The show's massive success in the mid-2000s and early 2010s spawned a number of imitating singing-competition shows, such as Rock Star, Nashville Star, The Voice, Rising Star, The Sing-Off, and The X Factor. Its format also served as a blueprint for non-singing TV shows such as Dancing with the Stars and So You Think You Can Dance, most of which contribute to the current highly competitive reality TV landscape on American television.
What dancing show featuring celebrities has been helped by American Idol?
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The answer: Dancing with the Stars


The problem: Answer a question about this article:
Hayek is widely recognised for having introduced the time dimension to the equilibrium construction and for his key role in helping inspire the fields of growth theory, information economics, and the theory of spontaneous order. The "informal" economics presented in Milton Friedman's massively influential popular work Free to Choose (1980), is explicitly Hayekian in its account of the price system as a system for transmitting and co-ordinating knowledge. This can be explained by the fact that Friedman taught Hayek's famous paper "The Use of Knowledge in Society" (1945) in his graduate seminars.
Which of Hayek's works did Friedman once teach?
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The answer:
The Use of Knowledge in Society