A carpentry shop currently sells 100000 decoy ducks per year at a cost of 14 dollars each. In the previous year when they raised the price to 21...

A carpentry shop currently sells 100000 decoy ducks per year at a cost of 14 dollars each. In the previous year when they raised the price to 21 dollars, they only sold 65000 decoy ducks that year. Assuming the amount of decoy ducks sold is in a linear relationship with the cost, what price should the carpentry shop charge per decoy duck to maximize their revenue?

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