Suppose the demand curve is: P = 300 - 2QD and the supply curve is: P = 100 + 3QS. What is the sum of the consumer and producer surplus in the market at the equilibrium price and quantity?

A. $3200

B. $1600

C. $2400

D. $4000

E. Cannot be determined from the information given.

Total surplus = 4000

so correct option is D. $4000

Explanation:

given data

P = 300 - 2QD

P = 100 + 3QS

to find out

sum of the consumer and producer surplus

solution

we first equating both as equilibrium at QD = QS

so

300 - 2Q = 100 + 3Q

solve we get

Q = 40

so P will be

P = 3 00 - 2 * 40

P = 220

Consumer surplus area above price and below demand so

Consumer surplus = 0.5 * (300 - 220) * 40

Consumer surplus = 1600

and

Producer surplus area above supply curve and below price so

Producer surplus = 0.5 * (220 - 100) * 40

Producer surplus = 2400

so Total surplus will be

Total surplus = Consumer surplus + Producer surplus

Total surplus = 1600 + 2400

Total surplus = 4000

so correct option is D. $4000