Simple interest formula:
[tex]I=P\cdot r\cdot t[/tex]I is the interest
P is the principal amount
r is the interest rate in decimals
t is the time in years
Future value formula (A):
[tex]A=P(1+r\cdot t)[/tex]___________
For the given situation:
1. Turn the time into years:
Bankers' Rule: 1 year is 360days
[tex]30\text{days}\cdot\frac{1\text{year}}{360\text{days}}=\frac{1}{12}\text{years}[/tex]2. Write the interest rate in decimal form:
[tex]\frac{2.5}{100}=0.025[/tex]What is the interest on the loan?:
[tex]\begin{gathered} I=325\cdot0.025\cdot\frac{1}{12} \\ \\ I=0.68 \end{gathered}[/tex]What is the loan's future value?
You can use the formula above or just add he interest to the principal amount:
[tex]\begin{gathered} A=325(1+0.025\cdot\frac{1}{12}) \\ \\ A=325.68 \end{gathered}[/tex]