A vendor can sell 200 souvenirs per day at a price of 250 ea

A vendor can sell 200 souvenirs per day at a price of $2.50 each. Each increase of 10¢ in price decreases the number of sales by 10 per day. Souvenirs cost the vendor $1.70 each. What price should be charged to maximize profit?

Solution

At $2.50, you sell 200 souvenirs at a profit of 80¢ for $160 profit.
At $2.60, you sell 175 souvenirs at a profit of 90¢ for $157.5 profit.
At $2.70, you sell 150 souvenirs at a profit of 100¢ for $150 profit.
At $2.80, you sell 125 souvenirs at a profit of 110¢ for $137.5 profit.
At $2.90, you sell 100 souvenirs at a profit of 120¢ for $120 profit.