Answer :
For unit price in case 100 for $0.55
[tex]\frac{0.55}{100}=0.005[/tex]For unit price in case 180 for $0.81
[tex]\frac{0.81}{180}=0.004[/tex]The one that is better to buy is 180 napkins
ANSWER
The unit price for the package of 100 napkins is approximately $0.005 per napkin.
The unit price for the package of 180 napkins is approximately $0.004 per napkin
Is better to buy 180 napkins