I got this question from that link only and could not understand the explanation.
That makes two of us
Nice brain teaser but this is not reflective of a gmat question.
but using GMAT concepts
let us first find the permutation of 4 letters from the word college = 7!/(7-4)! = 7!/3! = 840. So there are 840 different permutations.
From these combinations we need to discount half of the occurences where both L's and both E's occur. I'm a bit stumped here.
If someone can shed light on this train of thought that would be kind.
-talent is the desire to practice-