I was walking along the road one day when I spied a cord of some sort lying in my path. From my vantage point, as I was approaching the cord, I could not tell if it was knotted or not.
What is the probability that the cord was knotted?
You could go the method of just counting 2 out of 8 possible combos or to think intuitively. The first crossing doesn't matter as you can make a knot by first going over or under. However the second and the third crossing must alternate. The probablility that one alternates is .5 thus the probability that both alternate is .5*.5 = .25
Intuitive answer
