Answer:
The revised net worth rounded to three significant figures is $80.2 billion.
The donation to charity amounts to $100,250,000.
Explanation:
Initial net worth is $77.0 billion.
Stock gains are $3.20 billion.
Calculating new net worth: $77.0 billion + $3.20 billion = $80.20 billion.
Hence, new net worth to three significant figures is $80.2 billion.
One-eighth of a percent is calculated as (1/8 x 1) / 100 = 0.00125.
The charitable contribution amounts to 0.00125 X $80.2 billion = $100,250,000.
Alternatively, $80,200,000,000 divided by 100 results in $802,000,000.