Need this 3 question help. Please put the explanations too! thanks!

1. Suppose that a consumer's utility function for GoodAand GoodBis given byU= 2A+B.At the consumption bundle (A= 1,B= 2), what is this consumer's marginal rate of substitution ofAforB(MRSAB)? Round your answer to two decimal places.
2. 

The price elasticity of demand for gasoline would be greater (that is, more elastic) if O we measured the change in quantity of gasoline demanded over a longer time horizon. O the price elasticity of supply for gasoline was decreased. 0 there were fewer close substitutes for gasoline. O consumers preferred driving to taking public busses even more than they already do. Suppose the market for two-bedroom, 1-bathroom apartments in Beverly can be described by the following demand and supply curves: Q0 = 400- 0.2P Q5 = 0.1P - 20 1. What is the market equilibrium? 2. What are the price elasticity of demand and price elasticity of supply at the market equilibrium? Which side of the market is more elastic, demand or supply