What was the annual interest rate?

Answer:
The rate at which the loan was given is 4%
Step-by-step explanation:
Given in question as
The Amount loaned to his niece = $ 1200
Time period of loan = 2 years
Interest calculate at Simple interest method = $96
Now Let the Rate of interest apply = R
So, From Simple Interest formula :
SI = [tex]\frac{Principal \times Rate \times Time}{100}[/tex]
Or, 96 = [tex]\frac{1200 \times Rate \times 2}{100}[/tex]
Or, Rate = [tex]\frac{96}{24}[/tex]
I.e Rate = 4%
Hence The rate at which the loan was given is 4% Answer