Answer:
The interest rate is 5%.
Explanation
The appropriate formula to use here is as follows:
i = simple interest = p*r*t.
Let's solve this for i: divide both sides of the equation by p*t:
i
------ = r
p*t
Subbing $412.5 for i, $750 for p and 11 yrs for t, we get:
$412.50
-------------- = 0.05.
($750)(11)
The interest rate is 5%.