If $30,000.00 is invested in an account for 20 years. Find the value of the investment at the end of 20 years if the interest is: 6%simple interest

You want to calculate the interest on $30000.00 at 6% interest per year after 20 year(s).
The formula we'll use for this is the simple interest formula, or:

Where:

P is the principal amount, $30000.00.
r is the interest rate, 6% per year, or in decimal form, 6/100=0.06.
t is the time involved, 20year(s) time periods.
So, t is 20year time periods.
To find the simple interest, we multiply 30000 × 0.06 × 20 to get that: The interest is: $36000.00

Usually now, the interest is added onto the principal to figure some new amount after 20 year(s),
or 30000.00 + 36000.00 = 66000.00. For example:

If you borrowed the $30000.00, you would now owe $66000.00
If you loaned someone $30000.00, you would now be due $66000.00
If owned something, like a $30000.00 bond, it would be worth $66000.00 now.

If i’m not wrong i believe it is c

The answer is 1 because you have to flip the sign when dividing by negative number and 3