Home » » The demand and supply equations for a commodity are given respectively as D = 20...

# The demand and supply equations for a commodity are given respectively as D = 20...

### Question

The demand and supply equations for a commodity are given respectively as D = 20 - (1/2)P; S = 8 + (1/4)P. Recalling that at equilibrium, D = S, the equilibrium (P) and quantity (Q) can be obtained as

A)
P = 12, Q = 16
B)
P = 15, Q = 10
C)
P = 12, Q = 14
D)
P = 16, Q = 12

## Discussion (2)

• Given that D= S,
20-1/2p= 8+1/4p
20-8= 1/4p+1/2p
12= 3p/4
3p= (12)(4)
3P= 48
3p/3= 48/3
P= 16
Q= S or Q= D
Q= 8+1/4p
Q= 8+1/4(16)
Q= 8+4
Q= 12
Therefore, P= 16, Q= 12