{"blocks": [{"key": "637288ce", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "b7b3fa65", "text": "Randomly allocating Y ad impressions to X users", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "3ebf1ed1", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "ee98de7e", "text": "Given X users and Y impressions assigned uniformly at random, what is the expected number of impressions a particular user receives? What is the probability that a specific user sees at least one impression? What is the expected number of users who see at least one impression?", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "3b5c18e3", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "fb039efa", "text": "Model each assignment as Bernoulli with p = 1⁄X, then apply binomial expectation, complement rule, and linearity.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}