4)An invoice for computer parts totals $797, including $3.67 for shipping and insurance. The terms are 1/10, n/45. If this invoice is paid within 10 days, how much is owed? Round to the nearest cent.

5)The Oak House had a markup of $21.81 on an oak table that they sold for $77.99. Find (a) the cost, (b) the markup on cost. Round dollars to the nearest cent and rates to the nearest tenth of a percent.

6) Toys4U purchases tricycles for $25. The store's operating expenses are 22% of cost with a net profit of 12% of cost. Find the selling price of one tricycle.