to compare unit prices, you first have to find the unit prices
for whistles, the unit prices are:
$21.25/25=0.85
36/50=0.72
60/80=0.75
difference between the highest unit price and the lowerest: $0.85-$0.72=$0.13
Kazos: 10/25=0.40
18.5/50=0.37
27.20/80=0.34
so the highest unit price is $0.40