Determine the state of the market

The demand equation is $Q_d = 1000 - 20p$.

$$Q_d = 1000 - 20(12) \\ Q_d = 1000 - 240 \\ Q_d = 760 \text{ units}$$

The supply equation is $Q_s = 500 + 30p$.

$$Q_s = 500 + 30(12) \\ Q_s = 500 + 360 \\ Q_s = 860 \text{ units}$$

At p = \12.00$:$Q_d = 760$units$Q_s = 860$ units

Since $Q_s > Q_d$ ($860 > 760$), there is a surplus in the market.

The surplus is calculated as:

$$\text{Surplus} = Q_s - Q_d \\ \text{Surplus} = 860 - 760 \\ \text{Surplus} = 100 \text{ units}$$

The state of the market is a surplus of 100 units.