A supermarket sells 800 bottles of refreshments weekly for $1 (normal price). From time to time the shop sells the refreshments at a discount price...

A supermarket sells 800 bottles of refreshments weekly for $1 (normal price). From time to time the shop sells the refreshments at a discount price of $0.90 per bottle and the weekly demand increases then to 1000. The shop pays $0.40 for a bottle. Determine the linear demand function for the refreshments at the supermarket. Find the optimal supply of refreshments and the corresponding price per bottle. 

A supermarket sells 800 bottles of refreshments weekly for $1 (normal price). From time to time theshop sells the refreshments at a discount price of $0.90 per bottle and the weekly demand...