Question

A certain chain of ice cream stores sells 28 different flavors, and a customer can order a single-, double- , or triple-scoop cone. suppose on a multiple-scoop cone that the order of the flavors matter and that the flavors can be repeated.how many possible cones are there? ...?

Answer 1

Think about the cones with only 1 scoop of ice cream. Isn't it clear that there are 28 of those?
Now think about the two scoop cones. You have 28 choices for the first scoop and 28 choices for the second scoop.
So the number of possibilities is 28(28).
Now think of the 3 scoop cones.
You have 28 choices for the first scoop, 28 choices for the second scoop, and 28 choices for the third scoop or 28(28)(28) possibilities.
Add them all together and you have the total.

So it will be like this:
28^3+28^2+28

I hope my answer helped you.