We have points on a number lines, numbers basically, we'll call J, K, L and M.
We're interested in the lengths of line segments, which are the absolute differences of the numbers.
We have J between M and L. Let's say L < J < M.
We have some leeway, let's just pin down L=0. That's the origin of our number line.
Since ML=|M-L|=11 and L<M we conclude M=11. Our inequality is
0 < J < 11.
Now we have KL=|K-L|=|K|=14 so K=14 or K=-14
|KJ|=9.
Case 1: K=14, so 14-J=9 or 14-J=-9 so J=5 or J=23
Case 2: K=-14 so -14-J=9 or -14-J=-9 so J=-23 or J=-5
We choose J=5 as the only one satisfying L < J < M.
L=0, J=5, M=11, K=14, MJ=|M-J|=|11-5|=6
Answer: MJ=6
Let's check ML=11, good, KL=14, good, KJ=9, good.