Final answer:
To satisfy the UN's Millennium Aid Goal with a U.S. GDP of $20 trillion, $106 billion more aid is required.
Step-by-step explanation:
In order to determine how much more aid is required to satisfy the UN's Millennium Aid Goal, we first need to calculate 0.7% of the U.S. GDP.
0.7% of $20 trillion is:
0.7/100 * $20 trillion = $140 billion.
Since the total aid given by the United States is currently $34 billion, we can calculate how much more aid is required by subtracting the current aid from the target aid:
$140 billion - $34 billion = $106 billion.
Therefore, $106 billion more aid is required to satisfy the UN's Millennium Aid Goal if U.S. GDP was $20 trillion.