Suppose you're working for a social media company that has a feature similar to Facebook's newsfeed. The company has two options for serving ads within their Newsfeed:
- Out of every 25 stories, one will be an ad
- Every story has a 4% chance of being an ad
For each option, what is the expected number of ads shown in 100 news stories? If we go with the second option, what is the chance a user will be shown only a single ad in 100 stories? What about no ads at all?