if it costs 85 dollars for three hours and they are going to rent it for six you mulitply 85 by 2 (to get the cost for 6 hours) and you get 170 then you find 7 percent of 170 (which is 11.90) then you add that to the total. you get 181.90 dollars and then add 40 (which was the tip) and you get 221.90 dollars.
