Let's analyze the questions in the image to understand the situation.

Question 1:

• "What happens to total revenue if price falls along part B of the demand curve?"

In this type of question, it is testing your knowledge of the elasticity of demand.

• If demand is elastic (elasticity > 1), a decrease in price leads to an increase in total revenue.
• If demand is inelastic (elasticity < 1), a decrease in price leads to a decrease in total revenue.
• If demand is unit elastic (elasticity = 1), total revenue remains unchanged when the price changes.

The answer you selected was "Total revenue does not change because demand is unit elastic." This would be correct only if the demand curve is unit elastic along this specific part (B). However, since the answer was marked as wrong, the correct interpretation might be:

• If the demand in part B is elastic, total revenue would rise as price falls, so the correct answer is likely "Total revenue rises because demand is elastic."

Question 2:

• It asks about income elasticity and whether hamburgers are a normal or inferior good. Given that Jenna's income decreased, yet she purchased more hamburgers (from 50 kg to 60 kg), the demand for hamburgers is increasing as her income decreases, indicating negative income elasticity.

This suggests that Jenna considers hamburgers an inferior good, meaning she buys more when her income decreases. The correct answer is likely: "negative, so Jenna considers hamburger to be an inferior good."

Would you like more details on this? Here are five related questions to help expand your understanding:

1. What is the formula for calculating income elasticity of demand?
2. How does income elasticity differ between normal goods and inferior goods?
3. Can a good be both normal and inferior at different levels of income?
4. How does price elasticity of demand differ from income elasticity of demand?
5. What role does necessity vs. luxury play in determining income elasticity?

Tip: Always carefully consider the relationship between income changes and consumption patterns to determine whether a good is normal or inferior.