Answer:
One year: Between $132,000 and $480,000.
20 years: Between $2,640,000 and $9,600,000.
60 years: Between $7,920,000 and $28,800,000.
Explanation:
If it makes between 11,000 and 40,000 a month, you should take both values and average them or make an estimate. Since there are 12 months in a year, 11,000*12 = $132,000 minimum, 40,000*12 = $480,000 maximum.
In 20 years, 132,000*20= $2,640,000 minimum, 480,000*20 = $9,600,000 maximum.
In 60 years, 2,640,000*3 = $7,920,000 minimum, 9,600,000*3 = $28,800,000 maximum.
If you want to be more specific, you need to find the average number of times you make certain amounts of money per month to find how likely it is to make a certain amount.