Willow Consumes

Willow consumes only two goods, peanuts (x) and toothbrushes (y), and her preferences can be represented by the utility function U(x,y)=xy3 , with the marginal utility functions MUx=y3 and MUy=3xy2. Suppose Px=$5, Py=$3. Let W denote income. What is Willow’s Engel curve of x?

Group of answer choices

W/20

W/10

W/6

W/4