Estimation question

How many airports are in the US and in the World?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Estimation using known reference points and reasonable ratios to size two related quantities.

Anchor on a known reference: the US has around 5,000 public use airports, with roughly 500 handling commercial passenger traffic.
Estimate the world total by scaling relative to US land area and economic development, since airport density correlates with infrastructure investment.
Assume the world has roughly 4 to 5 times the airports of the US given its larger population and land area, landing near 20,000 to 25,000.
State clearly that the number varies hugely depending on whether small private airstrips are counted.
Cross check against a known reference point, such as commercial airports worldwide numbering around 40,000 when including smaller regional strips.
Present both numbers as ranges with the counting definition stated up front.

Explicitly separates public use versus commercial airports, since the definition changes the answer by an order of magnitude.
Anchors on a real reference number for the US before scaling to a global estimate.
States the scaling assumption clearly, e.g. assumes global count is 4 to 5 times the US given relative land area and development.
Presents ranges rather than false precision, acknowledging the definition dependent uncertainty.

Giving one number without stating whether it includes small private airstrips or only commercial airports.
Skipping any reference anchor and guessing from nothing.
Overly precise single numbers with no stated uncertainty.

Chapters of the AI PM course that teach what this question tests.