Answer: 10 years
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Work Shown:
A = final value = 38750
P = amount loaned = 25000
i = interest
i = A - P = 38750 - 25000 = 13750
Now apply the simple interest formula to solve for t.
i = P*r*t
13750 = 25000*0.055*t
13750 = 1375*t
t = 13750/1375
t = 10 years to pay off the loan
Side note: r = 0.055 is the decimal form of 5.5%