Economics of Small Decisions

Thirty questions on the economics hiding inside ordinary choices — not interest rates and GDP, but the trade-offs you make every day. Covers opportunity cost, the sunk cost fallacy, marginal vs. total cost, fixed vs. variable costs, incentives and their unintended consequences, scarcity and trade-offs, diminishing returns, and why something free so often still has a cost. It mixes concept-spotting (single-choice), find-every-cost scenarios (multiple-choice), and quick marginal-cost and percentage calculations (numeric input). Each question pairs a tempting wrong answer with an explanation that teaches the underlying idea, and every question carries Wikipedia references so you can verify it and read further.