You are working trying to estimate the proper price to charge

You are working trying to estimate the proper price to charge a market for the firm that sells beer in Lancaster Pennsylvania. They estimated that the demand curve for the market is Quantity demanded=20-2P. The firm currently prices the good at 8 dollars. They want to move the price to 6 dollars in a attempt to increase profits.This question is worth 5 points (please show work for full credit)

1) What is the elasticity for this move in price (Use the midpoint method for elasticity) make sure you show your work? (1.5)

2) Now you are contacted by a different branch of this company that is in a lower priced (Scranton P.A.) market with the same demand curve. They want to move the price from 2 to 5 dollars. What is the elasticity of this change (Use the midpoint method)?(1.5)

3) Now suppose you find out that there is a similar product that impacts the Quantity demanded for a product. The relationship is Qd=15+Pb. Now suppose the price (Pb) of the other good is 5 and goes to 6. What is the Cross-price elasticity of the good? what type of relationship is this (complement or substitute) (2)