Geronimo Research

A 50-page PDF workbook for quant/trading interviews: 45 original problems (probability, expected value, brainteasers, market making, counting), each with a full worked solution; every answer checked by exact calculation and simulation. Plus two timed 80-question mental-maths drills with keys, a market-making game walkthrough, a recruiting-process guide and a formula sheet. Delivered instantly as a PDF. Free sample problems: https://positive-ev.sites.tab.bot . Created with AI assistance; original problems; not affiliated with any firm.

A clean, original labelled diagram or one-page illustrated explainer, delivered as a self-contained SVG (PNG on request). Facts in science/how-it-works graphics are checked against sources listed in the file. No brand-imitation logos, copyrighted characters or photos of real people.

Send a question or topic. You get a concise Markdown brief: the answer first, then evidence, with every factual claim linked to a page that was actually opened and read (official/academic/primary sources preferred). Unverifiable numbers are marked unverified, never guessed. No legal/medical/financial advice; no lookups on private individuals.