Charis invested $140. She earned a simple interest of 3% per year on the initial investment. If no money was added or removed from the investment, what was the amount of interest Charis received at the end of two years?

$140 x 3% =

$140 x 3/100 =

$140 x 0.03 =$4.20 - simple interest for 1 year.

$4.2 x 2 =$8.40 - simple interest for 2 years.