$11 because you take ten off for every extra dollar above nine. If you do 9*130 you get $1170. If you do $10 you subtract ten from the 130 boxes of printer paper each week so that would be 130-10=120 then you multiply 120*10=$1200. If you do $11 you subtract twenty from the 130 boxes because that's two extra dollars, 130-20=110. 110*11= $1210. If you do twenty you have to subtract 30 boxes, 130-30=100. 100*12= 1200. Therefore, $11 per box would be the highest revenue for the company.
