1.If Dave has a three-year college loan for $10,000 and the lender charges a simple interest rate of 6 percent, Dave will have to pay $1,800 in interest. $10,000 principle at 6 percent annual interest rate is equal to a monthly interest payment of $50. 36 X $50 = $1,800.
2.If Joe borrowed $900 from Sam for six months and charges Joe a simple interest rate of 4 percent then Sam will earn $936.
good luck :)