Net 14

CBSE NET DECEMBER 2011 PAPER II

The number of nodes in a complete binary tree of height h (with roots at level 0) is equal to

(A) 20+21+……+2h
(B) 20+21+……+2h-1
(C) 20+21+……+2h+1
(D) 21+……+2h+1

Ans:-A

Explanation:-
A complete binary tree have 0 or 2 child per parent. So, count the number of nodes in each level, starting with the root, assuming that each level has the maximum number of nodes.
n=1+2+4+….2h-1+2h