The linear demand curve \( q = 20 - 4p \) is drawn in the usual way, with price on the vertical axis and quantity on the horizontal axis. Where does it meet the two axes?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Price axis at 5; quantity axis at 20
Price goes on the vertical axis and quantity on the horizontal axis.
Quantity axis (p = 0): q = 20 − 0 = 20
Price axis (q = 0): 20 − 4p = 0, so p = 20 / 4 = 5
Swapping the two numbers would put quantity on the price axis.
NCERT (2026-27): “Graphical Representation of a Function … The demand curve, for example, is drawn by taking the independent variable (price) along the vertical axis and the dependent variable (quantity) along the horizontal axis. …” “Linear Demand A linear demand curve can be written as d(p) = a – bp; … where a is the vertical intercept, –b is the slope of the demand curve. At price 0, the demand is a, and at price equal to a/b, the demand is 0. The slope of the demand curve measures the rate at which demand changes with respect to its price. For a unit increase in the price of the good, the demand falls by b units.” |