We will have that $2200 represent the 100%, then how much money does 12% represent.
In order to solve for the ammount of money we multiply the invested ammount ($2200) times the percentage we want to know (12%) and divide it by 100%, that is:
[tex]m=\frac{2200\cdot12}{100}\Rightarrow m=264[/tex]Here we can see, he earned $264 in those 2 years.
