The probability of a ball landing in bucket k is the number of paths to the bucket multiplied by the probability of each path: p(k) = n! k!( n " k)! 2"n Page 5 Clicker Question #1 For a 7-row plinko, with 8 buckets labeled 0 to 7, what is the probability of a ball landing in bucket 1?

The Mathematics of the Board\n\n At each level, the penny will be "knocked" either to the left or to the right, each with a 50/50 probability. p(left)^n1 p(right)^n2. But there will be many ways of taking n1 lefts and n2 rights over N levels. If all N choices are left, for instance, there is only one way.