SOLUTION: How much should you invest at 4.5% simple interest in order to earn $90 interest in 18 months?

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Question 1148365: How much should you invest at 4.5% simple interest in order to earn $90 interest in 18 months?
Answer by ikleyn(52879) About Me  (Show Source):
You can put this solution on YOUR website!
.

Interest  I = D*r*t,     (1)


where D is the original deposit amount, r is the rate, expressed as decimal,  and t is time in years.


In this problem,  r = 0.045, r = 18 months = 1.5 years.


So, the equation (1) takes the form


    90 = D*0.045*1.5,


which gives the ANSWER  D = 90%2F%280.045%2A1.5%29 = 1333.33 dollars.

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