Answer:
$25
Explanation:
Consumer surplus is defined as the difference between the price of a good or service and what a consumer is willing to pay for that good or service. Julia's surplus = $60 - $50 = $10
Supplier surplus is defined as the difference between the price of a good or service and the price at which the supplier would be willing to sell his goods or services. Andre's surplus = $50 - $35 = $15
total surplus = Julia's and Andre's surplus = $10 + $15 = $25