Need help with this question: A local pizzeria sells 500 large pepperoni pizzas per week at a price of $20 each. Suppose the owner of the pizzeria tells you that the price elasticity of demand for his pizza is -3, and he asks you for advice. He wants to know two things. First, how many pizzas will he sell if he cuts his price by 10%? Second, how will his revenue be affected?
If he cuts hiss price by 10%, his sales will increase to [?] pizzas, and his total revenue will increase to $ [?].
Please explain how to get answers, thanks.