The quantity demanded each month of russo Espresso Makers is 250 when the unit price is $140; the quantity demanded each month is 1000 when th e unit price is $110. the suppliers will market 750 expresso makers if the unit price is $60 or higher. At a unit price of $80 they are willing to market 2250 units Both the demand and supply equations are known to be liniear.

Question

The quantity demanded each month of russo Espresso Makers is 250 when the unit price is $140; the quantity demanded each month is 1000 when th e unit price is $110. the suppliers will market 750 expresso makers if the unit price is $60 or higher. At a unit price of $80 they are willing to market 2250 units Both the demand and supply equations are known to be liniear. 
A: Find the demand equation. 
B: Find the supply equation. 
C: Find the equilibrium quantity and the equilibrium price.

Steve · Answer

demand:
(d-250)/(p-140) = (1000-250)/(110-140)
d-250 = -25(p-140)
d = -25p + 3750

supply:
(s-750)/(p-60) = (2250-750)/(80-60)
s-750 = 75(p-60)
s = 75p - 3750

equilibrium:
-25p + 3750 = 75p - 3750
100p = 7500
p = 75
s = d = 1875