This one is kinda tricky,
So if we look at the clues, 1 and 2 represent red candies.
We need to think like a computer here, if we were scanning a bar code with our laser eyes and we see 1s and 2s as favorable in this case, we would see 5 favorable codes (there are 3 "1s" and 2 "2s"),
Therefore the answer should be 5.
Hope this helped.
