You and your college roommate eat three packages of Ramen noodles each week. After graduation last month, both of you were hired at several times your college income. You still enjoy Ramen noodles very much and buy even more, but your roommate plans to buy fewer Ramen noodles in favor of foods she prefers more. When looking at income elasticity of demand for Ramen noodles, yours would: a. be negative, and your roommate's would be positive b. be positive, and your roommate's would be negative c. be zero, and your roommate's would approach infinity d. approach infinity, and your roommate's would be zero.

The answer to this question is b. Yours will be positive and your roommate's would be negative.

Explanation:

Income elasticity of demand is the degree of responsiveness of demand to changes in income. In other words, it measures how changes in income of consumers will affect the quantity of commodities demanded by such consumers.

An income elasticity of demand can be positive or negative.

It is positive, when an increase in income leads to an increase in the quantity demanded by the customer. However it is referred to as negative when an increase in income leads to decrease in the quantity demanded by the consumer.    

In  the question above, it can be seen that the increase in income of the first person brought about increase in the commodity demanded thereby making his income elasticity of demand positive. one the other hand, the increase in the income of his roommate, brought about decrease in his demand which translate to the fact that his income elasticity of demand would be negative.

Hence the answer given.