Joe borrowed $900 from sam for six months. how much will sam earn if he charges joe a simple interest rate of 4 percent? $18 $216 $918

Simple interest of 4% means that joe have to pay 4% interest of 900 in the period of 1 yearsince joe only borrowed it for 6 months, you can find it with this formula : $900 x 6/12 x 4 % =   $18so the answer is $18

Ithink you're supposed to multiply 12.50 which is how much he makes per hour and then multiply it by each number then add whats left togrther and there's your answer