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TL;DR

AM-GM Optimization: A canonical quantitative trading interview question at foundation difficulty. Commonly asked at Jane Street, HRT, Optiver, SIG.

By Valenke Exam Prep Team·Last updated 2026-06-01
foundationReal Analysis & Inequalities

AM-GM Optimization

Asked at: Jane Street, HRT, Optiver, SIG

Problem
Find the minimum value of f(x)=x+4xf(x) = x + \frac{4}{x} for x>0x > 0. Then: a box with no top has surface area 108 square inches. Find the dimensions that maximize the volume.
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