probbality=desired outcomes/total possible outcomes
so you and 2 friends makes 3 people
you each order a differnt topping
so
7/14 or 1/2 of them are meat on first try
then, 1 less topping, so 6/14 or 3/7 are meat for 2nd peson
then 1 less topping so 5/14 are meat for 3rd person
1/2 times 3/7 times 5/14=15/196
probablity will be 15/196 or about 7.65%