Answer:
21 weeks/months/years
the unit is not clarified in the question.
Explanation:
First, we have to calculate the amount of interest added after each interest period. In this case, we know the interest rate is 7.5% so after each period, there will be extra 1875 dollars of interest.
25000 x 0.075 = 1875
Now, we find out how many periods of interest adds up to a sum of 39375. We just divide the amount of interest it's asking by the amount of interest after 1 period.
39,375/1875 = 21
boom, It will take 21 periods.