This is another beautiful puzzle that I got through my daughter (Anisha) and her friend (Abhiram), which they got in Alok Mittal’s Mathematical Circles class.
In a line up of 10 soldiers, what is the least number of soldiers that can be picked in order of either ascending or descending heights? Assume that no two soldiers have the same height. Soldiers can be picked from anywhere in the line, but their order of standing cannot be changed.
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