p = 7000 is the amount deposited, aka the principal
r = 0.15 is the decimal form of 15% interest rate
t = 2 is the number of years the money sits in the account
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B = p*(1+r)^t
B = 7000*(1+0.15)^2
B = 7000*(1.15)^2
B = 7000*(1.3225)
B = 9257.50
Subtract off the deposited amount to get the interest earned
i = B - p = 9257.50 - 7000 = 2257.50
Answer: 2257.50