TestBook

Question

In a Binary Search Tree, a key with value 5 was searched after traversing nodes with values 1,3,4,6,7,8,9 not necessary in the same order. Lets P is the probability that 3^rd element in the search path beginning from root is either 3 or 8, and N are the number of different orders possible in which given nodes can be traversed before finding node with value 5. Find  (N/10) + P

 

Please someone explain the solution.