The electric device carrying a current of 15.0 A for 30 seconds delivers approximately 2.81 billion billion electrons. This is calculated using the relationship between current, charge, and the charge of a single electron. Therefore, 2.81 \times 10^{21} electrons flow through the device during that time.
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The correct answer about the think tanks is 'both of these' since the Foundation for Economic Education was founded in 1946 and the Mont Pelerin Society in 1947. Furthermore, federal spending in the aftermath of World War II contributed to economic growth. The post-war period saw significant government investments that stimulated the economy. ;