Charlie's utility function is U(x,y)=xy². What is his marginalrate of substitution?

a.None of the choices are correct.

b.2y/x

c.y²/x

d.y/(2x)

Martin consumes only two goods--soda (S)and pizza (P)--and always in the same proportion of 1 pizza and 2 sodas. Martin's income is $30, the price of soda is $1 and the price of pizza is $4. What is Martin's optimal consumption bundle (S*,P*)?

a.(8,4)

b.(5,10)

c.(4,8)

d.(10.5)