Easy · Probability & Combinatorics · Numerical · ~4 min · #118

Real Roots from Random Coefficients

Real interview · Bank of America

$B$ and $C$ are independent and uniform on $[0, 1]$ . What is the probability that $x^2 + Bx + C = 0$ has real roots?

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Worked solution

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Reported in interviews

Bank of America· Global Markets Quantitative Strategies Summer AssociateGlassdoor interview reviews

Candidate-reported and unverified; the firm may phrase it differently or no longer ask it. The wording here is our own paraphrase, and the solution was written and checked independently of any answers posted at the source.

Concepts

DiscriminantConditioning on one variable

Relevant for

Quant ResearcherDesk Quant