We’re looking for cost per cupcake.
Option A: 15 cupcakes for $30
$30 / 15 = $2 per cupcake
Option B: 30 cupcakes for $56
$56 / 30 = $1.86666 (round to $1.87) per cupcake
Option C: 60 cupcakes for $100
$100 / 60 = $1.66666 (round to $1.67) per cupcake
Option C is the lowest unit price, and best deal