Answer:
$2.50
Step-by-step explanation:
Economic surplus is the sum of consumer and producer surplus.
Consumer surplus is the difference between the willingness to pay of a consumer and the price he pays for a good or service.
Producer surplus is the difference between the price of a good or service and the least amount a producer is willing to accept.
Economic surplus = $6 - $3.50 = $2.50
I hope my answer helps you.