The total charge delivered by the electric device is 450 C. This charge amounts to approximately 2.81 x 10^{21} electrons flowing through the device in 30 seconds. The calculations involve using the formulas for charge, current, and the charge of an electron.
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The United States primarily operates under a market economy , where supply and demand control economic decisions. It includes elements of private ownership, competition, and consumer choice, with some government regulation present. Overall, this system allows for significant individual freedom while balancing public interests. ;