For a decline in price, total revenue declines if the demand of the product is

🔑Key Points: 
Elasticity of Demand
Price elasticity of demand is an economic measurement of how the quantity demanded of a good will be affected by changes in its price. In other words, it’s a way to figure out the responsiveness of consumers to fluctuations in price.
When the price of a good or service influences consumer demand, this is known as elastic demand. Consumers will buy a lot more if the price drops just a little. If prices rise somewhat, they will reduce their purchases and wait for pricing to return to normal.
Inelastic demand is a term that economists use to refer to a situation where demand for an item remains the same, no matter how far its price rises or falls.
🛑Important Points: 
Total revenue is price multiplied by quantity demanded (TR = P x Qd).
Inelastic Demand case
 In the inelastic demand, a one percent change in the price results in a less than one percent change in the quantity demanded. A price increase will therefore increase total revenue, while a price decrease will decrease total revenue.

• Elastic Demand Case:
 In the elastic demand, the percentage change in quantity demanded is greater than the percentage change in price, so raising the price in this region of the demand curve will decrease total revenue while lowering the price increases total revenue.