beth put $8,000 in a savings account. at the end of a year the account had earned $720 in interest. what was…

beth put $8,000 in a savings account. at the end of a year the account had earned $720 in interest. what was the yearly interest rate on the account?\na 18.5%\nb 17.5%\nc 10.0%\nd 9.0%

beth put $8,000 in a savings account. at the end of a year the account had earned $720 in interest. what was the yearly interest rate on the account?\na 18.5%\nb 17.5%\nc 10.0%\nd 9.0%

Answer

Explanation:

Step1: Recall interest - rate formula

The formula for simple - interest is $I = Prt$, where $I$ is the interest, $P$ is the principal amount, $r$ is the interest rate, and $t$ is the time. In this case, $t = 1$ year, $I=$720$, and $P = $8000$. We need to solve for $r$. Since $t = 1$, the formula simplifies to $I=Pr$. Then $r=\frac{I}{P}$.

Step2: Substitute values

Substitute $I = 720$ and $P = 8000$ into the formula $r=\frac{I}{P}$. $r=\frac{720}{8000}=0.09$.

Step3: Convert to percentage

To convert the decimal to a percentage, multiply by 100. $r = 0.09\times100%=9.0%$.

Answer:

D. 9.0%