MathDB

3

Part of 2012 Grand Duchy of Lithuania

Problems(1)

line up 19 girls (all of different heights) in a row

Source: 2012 Grand Duchy of Lithuania, Mathematical Contest p3 (Baltic Way TST)

10/3/2020
How many ways are there to line up 1919 girls (all of different heights) in a row so that no girl has a shorter girl both in front of and behind her?
combinatorics