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Citadel Securities Interview Question

Citadel SecuritiesQuantitative Researcher Interview

If you toss a fair coin N times, what is probability that you will get an even number of heads? Follow up: now what if you have N - 1 fair coins, and the Nth coin is not fair, but lands on heads with probability p?

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Disclaimer: We are not affiliated with Citadel Securities in any way. This question is sourced from interviewees and public sources and may not be accurate or reflective of the company's actual interview process.