Calculate the price elasticity of demand when the price was increased from R25 to R40.

To calculate the price elasticity of demand, we need to use the formula:

Price Elasticity of Demand = Percentage Change in Quantity Demanded / Percentage Change in Price

First, let's calculate the percentage change in quantity demanded.

Percentage Change in Quantity Demanded = (New Quantity Demanded - Original Quantity Demanded) / Original Quantity Demanded

Assuming we have the original quantity demanded and the new quantity demanded, you can substitute those values into the equation to get the percentage change in quantity demanded.

Next, let's calculate the percentage change in price.

Percentage Change in Price = (New Price - Original Price) / Original Price

Again, assuming we have the original price and the new price, substitute those values into the equation to get the percentage change in price.

Lastly, substitute the calculated percentage changes in quantity demanded and price into the formula for price elasticity of demand to get the final result.

If you provide me with the original quantity demanded, new quantity demanded, original price, and new price, I can help you calculate the price elasticity of demand.