Question

Sophia invests money in an account paying simple interest. She invests $100 and no money is added or removed from the investment. After one year, she has $108. What is the simple percent interest per year? 

Answer 1

Simple percent interest per year is the interest earned divided by the principal multiplied by 100.

The interest earned is the final amount minus the initial amount, $108 - $100 = $8

To find the simple percent interest per year:

Simple Interest = (Principal x Interest rate x time) / 100

so

Interest rate = (Simple Interest * 100) / (Principal * time)

Plug in the values:

Interest rate = (8 * 100) / (100 * 1) = 8%

So the simple percent interest per year is 8%