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Probability and quant maths, explained.

Short, genuinely useful lessons on the ideas behind quantitative puzzles. Each guide starts with the answer or principle, then shows the reasoning and a problem you can try yourself.

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What is Daily Quant Daddy?

Daily Quant Daddy is an independent, free website featuring new probability, statistics and quantitative reasoning challenges each day. The guides above are permanent educational resources; they are not the answers to unreleased daily puzzles. We publish the explanations as readable HTML so they can be accessed without signing in or waiting for the calculator to load.

How to use these guides

Learn the key idea, follow the worked example and try the practice question before revealing the solution. When you're ready, return to the daily challenges to apply the method to a new problem. For site questions, see About and Contact.