Ascending and DescendingDiscrete Mathematics Level 5
Example: In the sequence of numbers 3-2-1-6-5-4-9-8-7, there are no 4 cards in either ascending or descending order (from left to right).
Details and assumptions:
- The 4 cards need not be adjacent to each other.
- The numbers are read from left to right in the line.
- Source: numberphile