For simple interest, we can make an equation.
Since we know that it will be 4 percent of 15,000, we need to find 4 percent of 15,000.
15,000×.04= 600
So 600 will be the amount Tran will receive every year.
15,000+600x=y
X is the amount of years and Y will be the total amount. The total amount we are looking at is double the starting value. 15,000 doubled is 30,000.
15,000+600x=30,000
We need to solve the equation by subtracting 15,000 from each side first.
600x=15,000
Now, let's divide 15,000 by 600.
15,000÷600=25
It will take 25 years for the account to double.