The yogurt can be any one of 3 flavors.
For each one . . .
The cookie can be any one of 6 choices.
For each one . . .
The syrup can be any one of 4 flavors.
The total number of different ways to combine them is
(3 x 6 x 4) = 72 different combinations.
Some of them may be totally yucky and nobody would want to eat them.
But we only care about the Math, not the personal tastes and preferences.
Think of it ! If you and 71 of your closest friends all go to the yogurt shop
together, it would be possible for every one of you to get a yogurt and
NOBODY to get the same combination that anybody else has !