Jessica has an account with a credit union. her account earns 2.5% simple interest yearly. exactly a year and a half ago, she opened her account with $900. how much interest has she earned so far?
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The interest earned by Jessica after a year and a half of investment is $ 33.75.

Step-by-step explanation:

First, we must establish that simple interest is one in which interests are not added to capital. Therefore, interest in this case will always be calculated on the initial basis of $ 900.

That said, if Jessica invested $ 900 in her account, and said account grants a simple annual interest of % 2.5 per year, that account grants an interest of $ 22.5 per year (since 900 x 2.5 / 100 = 22.5). Therefore, to know the interest obtained in a year and a half, we must perform the following calculation:

22.5 (annual interest) + 22.5 / 2 (half-year interest) = X

22.5 + (22.5 / 2) = X = 33.75

Therefore, the interest obtained by Jessica after a year and a half of investment is $ 33.75.