150 Most Frequently Asked Questions On Quant Interviews [patched]

Limits & Continuity Q3 - Q5: Derivatives, chain rule, partial derivatives Q6 - Q8: Integration techniques, definite and improper integrals Q9 - Q11: Multivariable calculus – gradient, Jacobian, Hessian Q12: Use Lagrange multipliers to optimize a function subject to constraints Q13 - Q14: Taylor series expansion and applications Q15 - Q16: First‑order ordinary differential equations, separation of variables Q17 - Q18: Second‑order linear ODEs, characteristic equations Q19 - Q20: Introduction to partial differential equations (PDEs) – heat equation, Black‑Scholes PDE Q21 - Q25: Linear algebra – matrix operations, determinants, rank, solving linear systems Q26 - Q30: Eigenvalues and eigenvectors, diagonalization, spectral decomposition Q31 - Q32: Covariance and correlation matrices – properties, positive semi‑definiteness, sum of eigenvalues of a correlation matrix Q33 - Q34: Vector spaces, inner products, orthogonality Q35: Numerical methods – Newton‑Raphson, finite differences, Monte Carlo integration

assuming the underlying follows GBM. Give an intuitive explanation of Ito's Lemma.

These questions assess your ability to think on your feet. The goal isn't always the "right" answer, but the logical path you take to get there.

: What are its key properties? Answer : Continuous paths, independent increments, normally distributed increments with mean 0 and variance t. 150 Most Frequently Asked Questions On Quant Interviews

with drift and volatility terms. Interpret each term economically.

How to implement a hash map and collision resolution methods?

“10 coins” puzzle (finding a counterfeit with a balance scale). Q85 - Q86: “100 prisoners” puzzle – optimization and strategy. Q87 - Q88: “Two ropes” – measuring 45 minutes using two ropes that each burn in 60 minutes but not uniformly. Q89 - Q90: “Ants on a stick” – collision problems. Q91 - Q92: “Blue‑eyed islanders” – logical deduction. Q93 - Q94: “The missing dollar” – accounting trick. Q95 - Q96: “Three doors” (Monty Hall). Q97 - Q98: “Circular table” – probability that a randomly placed leg leaves the table stable. Q99: “Heaven and Hell” (two doors, two guards) – logic puzzle. Q100 - Q101: “Poisoned wine” – information theory. Q102 - Q103: “Ball weighing puzzles” – optimal grouping strategies. Q104: “Two envelopes” – paradox. Q105 - Q106: “A bug walking along the edges of a triangle” – Markov chain and hitting probability. Q107: “Calendar cube” – forming all dates with two cubes. Q108: “Knight on a chessboard” – tour problems. Q109 - Q110: “Egg drop” – minimizing worst‑case drops. Limits & Continuity Q3 - Q5: Derivatives, chain

: Explain how this formula relates PDEs to expectations of stochastic processes.

: Explain antithetic variates, control variates, and importance sampling.

Linear algebra & matrix calculus (10)

Market microstructure & trading concepts (10)

: You have 1000 bottles of wine, one poisoned. With 10 test strips that can test multiple bottles at once, how many test strips are needed to identify the poisoned bottle? Answer : 10 test strips can identify 2¹⁰=1024 possibilities.