Question 1148365
.
<pre>

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 <U>ANSWER</U>  D = {{{90/(0.045*1.5)}}} = 1333.33 dollars.
</pre>

-------------


To see other similar solved problems and to feel a solid ground under your legs, look into the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/percentage/lessons/Simple-interest-percentage-problems.lesson>Simple interest percentage problems</A> 

in this site.