Remember that the formula for simple interest is:

Where I is the interest to paid, p is the loan, r is the interest rate (in decimal), and t is the time (in years).
A. We know that the interest rate for a loan of 9 months is 2.9%, but we need to convert that rate to decimal. To do that just divide the interest rate by 100%:

Next, we are going to find the time t in years. Since the period of time is 9 months, we are going to dive by 12, the number of months in a year, to obtain the time in years:

Now, we just need to replace the values in our formula to find the interest owned:

We can conclude that <span>the interest owed for a home improvement loan of $900 after 9 months is $19.58.
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B. Similarly:



We can conclude that the interest owed for a home improvement loan of $2500 after 18 months is $116.25.
C. Similarly:



We can conclude that the interest owed for a home improvement loan of $5600 after 6 months is $67.2