Exercise · ZW-CARDINAL-NUMBER-003 · ★☆☆ Basic

What does it mean for two sets \(A\) and \(B\) to be equinumerous?

Choose one option.

Show answer
  • B. That there is a bijection between \(A\) and \(B\)

Explanation

Equinumerous means there is a bijection between the two sets. It does not require them to be equal or finite.

Study Set theory in ZWMath →

Review the concept: Cardinal number

The cardinal number of a set \(A\) is the least ordinal equinumerous with \(A\). It measures the size of \(A\) and also works for infinite sets.

\[|A| = \min\{\alpha \in \mathrm{Ord} : \alpha \approx A\}\]

More practice problems: cardinal number

← ZW-CARDINAL-NUMBER-002 ZW-CARDINAL-NUMBER-004 →