Bifalgorithm post · Brisk · Chapter 1
Are the numbers 18 and 25 congruent mod 6?
Are the numbers 18 and 25 congruent mod 6? (Brisk · Chapter 1) — "the numbers 18 and 25 con- gruent mod 6? No. If we take groups of 6 out of 18 stones, we’ll g…
Ideas in this flowchart
- 18 and 25 are not congruent modulo 6.
- Numbers are congruent modulo 6 only when they have the same remainder after groups of 6 are removed.
- For 18, three groups of 6 are removed, leaving a remainder of 0.
- For 25, four groups of 6 are removed, leaving 24 and a remainder of 1.
- The remainders are different: 0 for 18 and 1 for 25.
