Please show how to solve

The consumer demand equation for tissues is given by q = (90 - p) where p is the price per case of tissues and q is the demand in weekly sales. On a separate sheet of paper that you will scan and upload, please answer the following questions: A) Determine the price elasticity of demand E when the price is set at $40. Show work. B) Is demand elastic or inelastic at a price of $40? What will happen to revenue if we raise prices? Explain. C) At what price should tissues be sold to maximize weekly revenue? SHOW WORK. D) How many cases of tissues would be demanded if they were sold at the price that maximizes weekly revenue? SHOW WORK. E) What is the maximum weekly revenue? SHOW WORK. Please put answers in alphabetical order on the page that you scan and upload as your answer to this