Question 1175783
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The problem (like so many we get here at this forum!) is poorly worded.<br>
Exactly as presented, the question can't be answered.<br>
There are 7 kinds of topping, and we decide to choose 3 of them.  The number of ways you can do that is, literally, "7 choose 3":<br>
{{{C(7,3) = 7!/((3!)(4!)) = 35}}}<br>
But the question that is asked is<br>
"How many combinations of 3 scoops of ice cream and 3 toppings are possible?"<br>
That suggests that we are also choosing combinations of different flavors of ice cream.  And since the number of flavors we can choose from is not given, that question can't be answered.<br>