How to solve this clash problem

Puzzles
#1

You are hungry, so you start preparing dinner.

Your dinner consists of N food items.
Each food item can be an apple, a banana, or a curry.
The order in which you eat them does not matter.
Calculate the number of possibilities for dinner.

For N = 3, there are 10 possibilities:
AAA, AAB, AAC, ABB, ABC, ACC, BBB, BBC, BCC, CCC

i thought that if N=3 then will be nnn way to arrange dinner??

#2

Looks like a basic combinatorial problem where you are expected to find possible combinations with replacement/repetition.

#3

It’s a combination where you select N items from 3 in set and they can repeat.

General formula:

C(n, r) = (r + n - 1)! / (r!( n - 1)!)

I guess n = 3 and r = N

We use combination instead of permutation when order of the data doesn’t matter.