Answer:
20 utils
Explanation:
In order to ensure consumer equilibrium, the ratio between the marginal utility and the cost per unit of all products must be the same.
In this case the marginal utility per dollar for both the Colby Jack cheese (C) and for the Swiss cheese (S) are:
[tex]\frac{U_C}{P_C}=\frac{U_S}{P_S} \\\frac{U_C}{\$4}=\frac{30}{\$6}\\ U_C = 20\ utils[/tex]
The person would have to get 20 utils from the last pound of Colby Jack cheese.