uppose that the U$.$S$.\text{'}$s real GDP per capita is $$60,000$ and its average annual growth rate over the past decade is $2\%.$ China's eal GDP per capita, in contrast, is $$15,000$ and its average annual growth rate over the past decade is $5\%.$

If the China's real GDP per capita continues to grow at $5\%$ per year, how many years will it take for its economy to double?

It will take China $$ years for its real GDP per capita to double

Assume that the USA's real GDP per capita experiences no growth moving forward, so that our GDP per capita remains $$60,000.$ If the Chinese economy keeps growing by $5\%$ per year, how many years will it take for China's economy to "catch$-$up$"$ to the USA's $$60,000$ in real GDP per capita?

It will take China

years for its real GDP per capita to catch up with the United States