Chapter 5/Elasticity and Its Application ❖ 85
In Figure 4, supply is perfectly inelastic and demand increased. As a result, the
quantity remained the same but price increased so Leonard’s explanation could be
correct. In Figure 5, demand is perfectly inelastic and it increased. As a result, both
the price and quantity increased so Sheldon’s explanation cannot be correct. In
7. a. If your income is $20,000, your price elasticity of demand as the price of
b. If the price is $12, your income elasticity of demand as your income increases
from $20,000 to $24,000 is [(30 – 24)/27]/[(24,000 – 20,000)/22,000] =
8. a. The percentage change in price (using the midpoint formula) is (1.50 – 1.25)/
9. Walt’s price elasticity of demand is zero, because he wants the same quantity
10. a. With a price elasticity of demand of 0.4, reducing the quantity demanded of
cigarettes by 20% requires a 50% increase in price, because 20/50 = 0.4. With
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Figure 8:
Raj’s
D
S1
Price of
coee
Quantity of