if you invest $8,600 at a 3.95% simple annual interest rate, approximately how long will it take for you to…

if you invest $8,600 at a 3.95% simple annual interest rate, approximately how long will it take for you to have a total of $21,000?\na. 25.3 years\nb. 36.5 years\nc. 45.9 years\nd. 60.7 years

if you invest $8,600 at a 3.95% simple annual interest rate, approximately how long will it take for you to have a total of $21,000?\na. 25.3 years\nb. 36.5 years\nc. 45.9 years\nd. 60.7 years

Answer

Explanation:

Step1: Find the interest amount

The total amount $A = 21000$ and the principal $P=8600$. The interest $I=A - P$. So, $I = 21000 - 8600=12400$.

Step2: Use the simple - interest formula

The simple - interest formula is $I = Prt$, where $P$ is the principal, $r$ is the annual interest rate (in decimal form), and $t$ is the time in years. Given $r = 3.95%=0.0395$. We need to solve for $t$. Rearranging the formula for $t$ gives $t=\frac{I}{Pr}$.

Step3: Calculate the time

Substitute $I = 12400$, $P = 8600$, and $r=0.0395$ into the formula for $t$. $t=\frac{12400}{8600\times0.0395}=\frac{12400}{339.7}\approx36.5$.

Answer:

b. 36.5 years