Suppose that each firm has the cost function cy) y+4 for y> 0 and c(0) = 0. Marginal cost is MC(y)-2y. With Industry demand given by Dip)=50-p, the equilibrium price and equilibrium number of firms in the Industry (In that order) will be $4 and 23. $8 and 21. $2 and 24 $6 and 22. $1 and 50.