Answer:
3 times rebate will maximize its revenue
Step-by-step explanation:
Given that a store has been selling 300 DVD burners sold per week at 350 each
A market survey indicates that for each $ 30 rebate offered to buyers, the number of units sold will increase by 60 a week.
If x times rebate is offered then units sold would be 300+60x
Thus original revenue
After rebate of x times 30 dollars we have
New revenue

Equate first derivative to 0 to get
x=
i.e. 3 times rebate will maximize its revenue