what is the equilibrium condition and quantityi n the market

Question

The demand for pocket calculators is given by the functions: p=72-1/2Qd and the supply is given by the  function 120=Qs-p where Qd= quantity demanded Qs= quantity supplied and p=price. what is the equilibrium condition solve for the equilibrium price and quantity in this market

Answer 1

Easiest method of solution is to solve both equations for Quantity, both Qd and Qs

 

Solving the first equation for Qd yields

 

p = 72 - 1/2Qd

 

1/2Qd = 72 - p or Qd = 144 - 2P

 

Solving the second equation for Qs yields

 

120 = Qs -p

 

Qs = 120+p

 

For equilibrium, we set the Qs to the Qd

 

144 - 2P = 120 + p

3P = 24

P = 24/3 = 8

and Qd = 144-2*8 = 128 and Qs = 128 +8 = 128

 

Therefore Qd and Qs is 128 units at a price (P) of $8

 

Hope this helps