If a is the mean and b is the median of nine consecutive integers, what is the value of |a - bl?

It would be zero.

Step-by-step explanation:

Let's for example look at this list : 123456789

The mean is 5, and the median would also be 5.

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.