.
.
. .
.
Subj:.....Find The Missing Number IV (S618)
          by Philip J. Carter and Kenneth A. Russell 
          From the book "IQ Test" on 11/8/2008 
             Published by Sterling Pub. Co., Inc., 2008 
             387 Park Avenue South, New York, N.Y. 10016 
             Test #9, Problem #39, Page 167 

What number should replace the question mark?

219, 208, 186, ?, 109, 54, and -12 
 
 
 
 

                THE SOLUTION

The answer is 153.

The differences are:
-11,  -22,  -33,  -44,  -55,  and  -66
.
.
.

.