12. SALES Last month, a retailer sold 120 jar candles at $30 per candle. This month
the retailer is considering putting the candles on sale. They estimate that for each
$2 decrease in price, they will sell 10 additional candles.
a. How much should the retailer charge for each candle in order to maximize its profit?
b. Find the domain and the range in the context of this situation.