Romeo and Juliet are the only two consumers in an economy with two goods x and y, and Romeo's endowment is R=(0,1) while Juliet's is J=(1,0) . They each choose their consumption levels of the goods independently.

(a) Is [0.5,0.5;0.5,0.5] a Walras equilibrium? Explain why or why not.

(b) Is it Pareto efficient? Explain why or why not.