Question 1003495
Model {{{y=p*e^(0.04*t)}}} and you will later use y=100000 and t=30.


{{{p=y/(e^(0.04*t))}}}


Substituting the values and resorting to a scientific calculator or other equipped resource, 
{{{p=100000/(e^(0.04*30))}}}


{{{p=100000/e^(1.2)}}}


{{{highlight(p=30120)}}}-----Initial investment amount.