In question 2, aren't the number of ways supposed to be variation and the number of options - combinations? That makes more sense.

Hey Avto, Thank you for engaging with our Probability course! I'm afraid I don't understand your question very well. Is 'Question 2' a question from any of the exams or are you referring to the video? Kind regards, 365 Hristina

Hi Hristina! I refer to question 2 of the exercise file. I think I've resolved an issue. Just for clarification, "the number of different options" refers to the variations, and "how many ways we can pick" refers to the combinations right? Because picking is a combination, while option takes into consideration different ways we can distribute the campaigns. Thanks in advance, Avtandil

Hey Avtandil, Thank you for the clarification! Yes, that is exactly correct! For the first two questions what matters is which banner we use for the different platforms, so, as you point out, it deals with distributing the banners. The last two question, on the other hand, don't care about how we are going to distribute the banners. It doesn't matter whether we are going to pick the 2nd and the 5th banner, or the 5th first and then the 2nd. Therefore, combinations are used. Hope this makes things clearer! Kind regards, 365 Hristina