Question

The price of bananas rises from ₹10 per kg to ₹14 per kg, due to which quantity demanded falls from 30 kg to 26 kg. What is the slope of the demand curve?

• A. –1
• B. –2
• C. –4
• D. –0.5

Hint:

The slope of a normal demand curve is always negative because of the "Law of Demand," which states that price and quantity demanded move in opposite directions. If you get a positive number for a standard demand curve, double-check your subtraction!

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The slope of a demand curve represents the change in price per unit change in quantity demanded. It is generally negative due to the inverse relationship between price and demand.
Step 2: Key Formula or Approach:
The formula for the slope of the demand curve is:
\[ \text{Slope} = \frac{\Delta P}{\Delta Q} \]
Where:
\( \Delta P \) = Change in Price
\( \Delta Q \) = Change in Quantity
Step 2: Detailed Explanation:
Calculate the change in price (\( \Delta P \)):
\[ \Delta P = P_2 - P_1 = 14 - 10 = 4 \]
Calculate the change in quantity demanded (\( \Delta Q \)):
\[ \Delta Q = Q_2 - Q_1 = 26 - 30 = -4 \]
Apply the values to the slope formula:
\[ \text{Slope} = \frac{4}{-4} = -1 \]
Step 3: Final Answer:
The slope of the demand curve is –1.