please explain

. Let demand be P(Q) = 6 %Q. What is the price elasticity of demand at Q = 4? 1 4 b. =-% c. =-4 d =2 . Suppose we have 3 types of households each with private demand for a public good (like ood protection) of 13103) = 5, Pz(Q) = 10 Q, and Pam) = 20 - 2Q. What is the social demand curve for the range Q 0). What does that tell us about the demand elasticity at that point? a. e > -1 b. e