A manufacture has been selling 2000 television sets a week at 390 each A market survey indicates that for each 30 rebate offered to a buyer the number of sets sold will increase by 300 per week a Find the demand function p x where x is the number of the television sets sold per week 1 10 I p x X b How large rebate should the company offer to a buyer in order to maximize its revenue c If the weekly cost function is 130000 130x how should it set the size of the rebate to maximize its profit