On platform X, 60% of stories are fake news. Fake news stories have an 80% chance of getting at least 500 likes, while real stories have a 30% chance of getting at least 500 likes. If you see a story with at least 500 likes, what is the probability it is fake news?

Let F = “story is fake news” R = “story is real” L = “story has at least 500 likes” Given: P(F) = 0.6 P(R) = 0.4 P(L | F) = 0.8 P(L | R) = 0.3 By Bayes’ theorem, \begin{equation} P(F | L) = \frac{P(L|F)P(F)}{P(L|F)P(F) + P(L|R)P(R)} \end{equation} \begin{equation} P(F | L) = \frac{0.8 \cdot 0.6}{0.8 \cdot 0.6 + 0.3 \cdot 0.4} = \frac{0.48}{0.6} = 0.8 \end{equation}

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Interview Questions Probability and Statistics Theory Fake News

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def two_sum(nums, target):
    seen = {}
    for i, n in enumerate(nums):
        if target - n in seen:
            return [seen[target - n], i]
        seen[n] = i
    return []

print(two_sum([2, 7, 11, 15], 9))  # [0, 1]

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