Elmer's utility function is U(x, y)  minx, y².If the price of x is $20, the price of y is $30, and Elmer chooses to consume 4 units of y, what must Elmer's income be?

A) $540
B) $880
C) $440
D) $200
E) There is not enough information to tell.

To find Elmer's income, we need to use the fact that he chooses to consume 4 units of y. Let's set up the equation:

U(x,4) = min{10x, 4y}

We know that the price of x is $20, so we can rewrite the equation:

U(20,4) = min{200, 120}

Since Elmer chooses to consume 4 units of y, we know that the minimum is 120. So:

U(20,4) = 120

Now we can use the utility function to solve for Elmer's income:

U(x,y) = 10 min{x, y}

120 = 10 min{20, 4}

120 = 10(4)

120 = 40x

x = $440

So Elmer's income must be $440.