Here, again, are the GDP per capita numbers for a number of countries shown in class. But rather than focus on welfare now, let us consider the effects of differences in growth rates on how the GDP ranking between countries evolves over time. (a) Suppose that the U.S. growth rate of real GDP/capita will equal what it has been over the past 100 or so years: about 2% per year. How long will it take U.S. GDP/capita to double? (b) Suppose that China will grow at the rate 6% per year over the foreseeable future (a rate that is lower than in its recent times). How long will it take China to double its GDP/capita?