The amount of interest after 3 years will be $15.
The complete question is given below.
You loaned a friend $100 and will charge him 5% annual simple interest when he pay it back. What is the amount of interest after 3 years?
Simple interest is the concept that is used in many companies such as banking, finance, automobile, and so on.
The interest is given as
I = (P × R × T) / 100
Where, P is the initial amount, R is simple interest rate, and T is the time.
We have
P = $100
R = 5%
T = 3 years
Then the interest will be
I = (100 × 5 × 3) / 100
I = $15
More about the simple interest link is given below.
https://brainly.com/question/2793278
#SPJ1