The value of interest rate should be 0.085.
We have given that the interest rate is 8.5% So we have given in percentage form but we use always decimal form of interest.
To convert a percentage to a decimal, divide by 100.
So the decimal form of the 8.5% is calculated by
[tex]\frac{8.5}{100}=0.085[/tex]
Therefore the option c is correct.
Therefore we use the interest rate is 0.085.
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