**Im having some trouble trying to find out why the correct answer to this question is 4. Could anyone be kind enough to briefly explain why? Thanks in advanced! Here's the question:** 

Consider the array a with values as shown:

4, 7, 19, 25, 36, 37, 50, 100, 101, 205, 220, 271, 306, 321

where 4 is a [0] and 321 is a [13] . Suppose that the search method is called with 
first = 0 and last = 13 to locate the key 205. How many iterations of the while loop must be made in order to locate it?