A cheque-cashing store is in the business of making personal loans to walk-up customers. The store makes one-week loans at 7 percent interest per week.

a. What APR must the store report to its customers? What is the EAR that the customers are actually paying?

b. Now suppose the store makes one-week loans at 9 percent discount interest per week. What’s the APR now? The EAR?

c. The cheque-cashing store also makes one-month add-on interest loans at 7 percent discount interest per week. Thus, if you borrow $100 for one month (four weeks), the interest will be ($100 × 1.074) − 100 = $31.08. Because this is discount interest, your net loan proceeds today will be $68.92. You must then repay the store $100 at the end of the month. To help you out, though, the store lets you pay off this $100 in installments of $25 per week. What is the APR of this loan? The EAR?