Suppose a quantity penalty applies on purchases of a good.

Suppose a quantity penalty applies on purchases of a good. Specifically, the pricing arrangement is such that a consumer can purchase the first 10 units of the good for $4 each and all additional units (i.e., the 11th, 12th, etc.) can be purchased for $8 each. If the consumer has an income of $200, what is the maximum number of units of the good that the consumer can purchase?