Answer:
721
Step-by-step explanation:
The possible combinations are 6 but one need to be careful when answering the question because of the clause "none or some"
The product rule says that if there are N ways of doing something and M ways of doing another thing, the number of ways of doing both things is equal to NM similarly if a third thing O is introduced then number of ways of combining the 3 items is NxMxO same for all numbers of combination
Since the order doesn't matter then the number of possible combination for 6 different topping is
1x2x3x4x5x6 or 6! = 720 however since the pizza can have none then should also be considered as a single combination so the total combination is 721
