Rosa invested 600 at 3.9% simple interest. At the investment's maturity, its value was 1302. How long was the money invested? Select one: a. 35 years b. 25 years c. 30 years d. 40 years

## Step 1: Calculate the total interest earned.<br />### The maturity value is the sum of the principal and the interest earned. The total interest earned is the maturity value minus the principal. $I = 1302 - 600 = 702$.<br /><br />## Step 2: Convert the interest rate to a decimal.<br />### Divide the percentage by 100 to convert it to a decimal. $r = \frac{3.9}{100} = 0.039$.<br /><br />## Step 3: Use the simple interest formula to find the time.<br />### The simple interest formula is $I = Prt$, where $I$ is the interest, $P$ is the principal, $r$ is the rate, and $t$ is the time. We have $I = 702$, $P = 600$, and $r = 0.039$. We need to find $t$. So, $702 = 600 \times 0.039 \times t$. $702 = 23.4t$. $t = \frac{702}{23.4} = 30$.