Question

A graph has quantity on the x-axis and price on the y-axis. A supply line goes through (10, 25), (20, 30), (30, 35), (40, 40).A graph has quantity on the x-axis and price on the y-axis. A demand line goes through (10, 40), (20, 30), (30, 20), (40, 10).
Based on the supply graph and the demand graph shown above, what is the price at the point of equilibrium?
a.
20
b.
30
c.
40
d.
There is not enough information given to determine the point of equilibrium.



Please select the best answer from the choices provided


A
B
C
D

Answer 1

B

Set supply = demand.
Supply: P = 0.5Q + 20 (from points given).
Demand: P = −Q + 50.
Solve 0.5Q + 20 = −Q + 50 → 1.5Q = 30 → Q = 20. Then P = 0.5(20) + 20 = 30.