Joe borrowed $900 from Sam for six months. How much will Sam earn if he charges Joe a simple interest rate of 4 percent?

Simple interest

you can charge it monthly or yearly

find 4% and multiply by how many months or years

4% of 900=

0.04 times 900=36

that is each time the interst is added

if it is monthly, (6months so) 6 times 36=216

if it is yearly (6months=1/2year so) 6 times 1/2=3

if it is taken monthly, then Sam earns $216

if it is taken yearly, then Sam earns $3