Refer to the demand schedule shown in Table 4P-1. For each price change, say whether demand is elastic, unit-elastic, or inelastic, and say whether total revenue increases, decreases, or stays the same.

Consider each of the following price increase scenarios.

a. Price increases from $10 to $20. Demand is _____ and total revenue _____.

b. Price increases from $30 to $40. Demand is _____ and total revenue _____.

c. Price increases from $50 to $60. Demand is _____ and total revenue _____.