A deli sells 640 sandwiches per day at a price of 
0.10 reduction in the price, 20 more sandwiches will be sold. How much should the deli charge in order to maximize revenue?
B) A different market survey shows that for every 
8 price, 10 more sandwiches will be sold. Now how should the deli charge in order to maximize revenue?
Solution:-
A) The deli should charge 
8 for a sandwich to maximize revenue.