All Fermi answers
Fermi #10 · Question 1

If a cheetah could hold its top speed the whole way, how long would it take to run the Boston Marathon?

Explore the official answer and the simple reasoning behind this Fermi estimate.

1QUESTION 1 OF 3

Answer & explanation

The official answer, with Fermi’s reasoning step by step.

Answer & explanation

Official answer

26

minutes

How to estimate it

Fermi’s official “Napkin math”

A cheetah is the fastest thing on land, about as fast as a car cruising on the highway. Call it 60 miles an hour. A marathon is about 26 miles.

Marathon
26 mi
Cheetah top speed
÷ 60 mph
26 ÷ 60 of an hour
≈ 26 min

Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.

Source calculation & reference
Fastest recorded cheetah (Sarah, Cincinnati Zoo, 2012)
= 61 mph (98 km/h)
Marathon distance
= 26.2 miles
26.2 ÷ 61
≈ 0.43 hours
≈
26 minutes

Reference cited by Fermi: Cincinnati Zoo and Guinness World Records cheetah speed record (Sarah, 2012)

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