mandy made $1,260 in interest by placing $9,000 in a savings account with simple interest for 1 year. what…

mandy made $1,260 in interest by placing $9,000 in a savings account with simple interest for 1 year. what was the interest rate? use the formula $i = prt$, where $i$ is the interest earned, $p$ is the principal (starting amount), $r$ is the interest rate expressed as a decimal, and $t$ is the time in years.

mandy made $1,260 in interest by placing $9,000 in a savings account with simple interest for 1 year. what was the interest rate? use the formula $i = prt$, where $i$ is the interest earned, $p$ is the principal (starting amount), $r$ is the interest rate expressed as a decimal, and $t$ is the time in years.

Answer

Explanation:

Step1: Reorganizar la fórmula para r

Dado $i = prt$, despejamos $r$. Dividimos ambos lados de la ecuación por $pt$, entonces $r=\frac{i}{pt}$.

Step2: Sustituir valores

Tenemos $i = 1260$, $p = 9000$ y $t = 1$. Sustituyendo en la fórmula $r=\frac{1260}{9000\times1}$. $r=\frac{1260}{9000}= 0.14$.

Step3: Convertir a porcentaje

Para convertir un decimal a porcentaje, multiplicamos por 100. Entonces $r = 0.14\times100 = 14%$.

Answer:

14%