Question

What is the maximum number of keys that a B+ -tree of order 3 and of height 3 have?

(a) 3

(b) 80

(c) 27

(d) 26

I'm obligated to ask this question of B-Trees topic in chapter B-Trees of Data Structures & Algorithms I

I got this question in a job interview.

Answer 1

Correct option is (d) 26

To explain: A B+ tree of order n and height h can have at most n^h – 1 keys. Therefore maximum number of keys = 3^3 -1 = 27 -1 = 26.