Question

My cousin borrowed $15,000 for a new car loan for 5 years. He told me that at the end of the loan, he had paid $21,000 for the interest and principal. What was the rate of the loan? A. 7% B. 8% C. 9% D. 10%

Answer 1

To solve this problem we are going to use the simple interest formula: $A=P(1+rt)$
where
$A$ is the sum of the interest and the principal
$P$ is the principal
$r$ is the interest rate in decimal form 
$t$ is the time in years

We know for our problem that $A=21000$, $P=15000$, and $t=5$. Now, let $x$ represents our interest rate. To express the interest rate in decimal form, we are going to divide the rate by 100%:
$r= \frac{x}{100}$
$r=0.01$.
Now that we have all the values we need, lets replace them in our simple interest formula to find the interest rate:
$A=P(1+rt)$
$21000=15000[1+(0.01x)(5)]$
$\frac{21000}{15000} =1+0.05x$
$1+0.05x=1.4$
$0.05x=0.4$
$x= \frac{0.4}{0.05}$
$x=8$

We can conclude that the interest rate of your cousin's loan was 8%.

Answer 2

Answer:

Hi it is 8. I'm the brainiest

Step-by-step explanation: