All Fermi answers
Fermi #17 · Question 2

How many pips are on a full set of double-six dominoes?

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

2QUESTION 2 OF 3

Answer & explanation

A standard double-six set

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

Answer & explanation

Official answer

168

pips

How to estimate it

Fermi’s official “Napkin math”

A double-six set has 28 tiles. Each half of a tile runs from blank up to six, so the average half is about three. That puts the average tile at six pips.

Tiles in a set
28
Average pips per tile
× 6
28 × 6
= 168

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

Source calculation & reference
Tiles in a double-six set
= 28
Each number 0 to 6 appears on 8 tile halves
= 8 × (0+1+2+3+4+5+6)
8 × 21
= 168

Reference cited by Fermi: Standard double-six domino set composition

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