Brand w: 500 napkins for $2.87

brand x: 200 napkins for $1.27

brand y: 100 napkins for $0.62

brand z: 250 napkins for $1.37

a. which brand is the cheapest? what is the cost of one napkin of this brand?

b. which brand is the most expensive? what is the cost of one napkin of this brand?

explain.