The following equations represent the demand for and supply of a product respectively. Q = 1000 − 2P and Q = 800 + 3P. a) Calculate the equilibrium price and quantity. b) Calculate the market situation at a price of 60. c) Calculate the market situation at a price of 20.

$$Q_D = Q_S$$ $$1000 - 2P = 800 + 3P$$

$$1000 - 800 = 3P + 2P$$ $$200 = 5P$$ $$P = \frac{200}{5}$$ $$P = 40$$

Using the demand equation:

$$Q = 1000 - 2(40)$$ $$Q = 1000 - 80$$ $$Q = 920$$

The equilibrium price is \boxed{P = \40}$and the equilibrium quantity is$\boxed{Q = 920 units}$.

$$Q_D = 1000 - 2(60)$$ $$Q_D = 1000 - 120$$ $$Q_D = 880 \text{ units}$$

$$Q_S = 800 + 3(60)$$ $$Q_S = 800 + 180$$ $$Q_S = 980 \text{ units}$$

Since $Q_S (980) > Q_D (880)$, there is a surplus.

$$\text{Surplus} = Q_S - Q_D = 980 - 880 = 100 \text{ units}$$

At a price of $60, there is a \boxed{surplus of 100 \text{ units}}$.

$$Q_D = 1000 - 2(20)$$ $$Q_D = 1000 - 40$$ $$Q_D = 960 \text{ units}$$

$$Q_S = 800 + 3(20)$$ $$Q_S = 800 + 60$$ $$Q_S = 860 \text{ units}$$

Since $Q_D (960) > Q_S (860)$, there is a shortage.

$$\text{Shortage} = Q_D - Q_S = 960 - 860 = 100 \text{ units}$$

At a price of $20, there is a \boxed{shortage of 100 \text{ units}}$.