Final answer:
The total cost of Lisa's purchase is $34.05. She pays with a $50 bill, thus she should receive $15.95 in change. The subject is Middle School level Mathematics, focusing on basic arithmetic and money transactions.
Step-by-step explanation:
The subject of this question is Mathematics, specifically dealing with basic arithmetic and money transactions. Lisa is purchasing packages of napkins and plates, then paying with a $50 bill. We must calculate the total cost of the items and then determine the change she should receive. The problem is at a middle school level.
Lisa bought five packages of napkins at $2.68 per package. Therefore, the total cost for the napkins is:
5 packages × $2.68 per package = $13.40
She also bought seven packages of plates at $2.95 per package. The total cost for the plates is:
7 packages × $2.95 per package = $20.65
The combined total cost for both napkins and plates is:
$13.40 (napkins) + $20.65 (plates) = $34.05
Since Lisa pays with a $50 bill, the change she should receive is calculated by subtracting the total cost from $50:
$50.00 - $34.05 = $15.95
So, Lisa should receive $15.95 in change.