Layaway plans permit you, for a fee, to pay for the item over the period of time and then receive item when you finish paying for it. In November 2011, Senator Charles E. Schumer of New York warned that holiday layaway programs currently reinstated by several popular retailers were, when you took fees into account, charging interest at the rate significantly higher than highest credit card rates. Assume that you bought the $79 item on November 15 on layaway, with final payment due December 15, and that retailer charged you a $5 service fee. Thinking of fee as interest, what simple interest rate r would be paying for layaway plan?