​A single, working parent decides to have a home delivery service perform his weekly grocery shopping. The service charges a fee of 6.5% of the food price, plus 50 cents per mile. In one month, for this parent, the service delivered food worth $1,652.88 and drove a total of 98 miles. Determine the parent's total cost for the groceries and the service during this month.

A contract requires payments of $1,500, $2,000, and $1,000 in 100, 150, and 200 days, respectively, from today. What is the value of the contract today if the payments are discounted to yield a 3.5% simple interest rate of return?

Tony Chang gives good customers a cash discount of 1.5% on any amount that they pay within 5 days of the invoice date. An invoice for $1,890 was written on February 2. The customer paid $900 on February 6. Compute the amount that Tony must credit to his customer's account. (This problem involves the partial payment of an invoice within the discount period.)​