Final answer:
The ice cream shop offers 240 different dessert combinations when taking into account all flavors, cones, and optional toppings.
Step-by-step explanation:
To calculate how many different desserts can be ordered at an ice cream shop with 12 flavors of ice cream, 5 types of cones, and 3 toppings, where a customer must choose one flavor and one cone, and may choose one topping (optional), we use basic combinatorics. First, for each ice cream flavor (12 options), there is a choice of cone (5 options), making 12 x 5 = 60 basic combinations without toppings. Since a topping is optional, each of these combinations could be without a topping, or with one of the three toppings, giving us 60 x (1 + 3) = 60 x 4 = 240 total dessert combinations (since the 'no topping' option is also a valid choice).