Answer:
$15
Step-by-step explanation:
Consumer surplus is the price the consumer pay for good/service minus the amount the consumer is willing to pay for it.
✓Mr. and Dr. Brown would be willing to pay $31
✓Mr. Smith would be willing to pay $28
✓Professor Jones and Mr. Jones would be willing to pay $22
Elizabeth PRICE for babysitting each set of children for an evening = $22
Consumer surplus= Σ (price that the consumer is willing to pay- Price of the good/service is sold)
= [(31-22)+(28-22)+(22-22)]
= 9+6+0
=$15
Hence, Consumer surplus is $15