Its similar to if a = b and b = c, then a = c. If I is greater than M and M is greater than N, than N is less than all other variables, so N

Think about it on a number line:

I is going to be the furthest to the right, then M, then finally, N.

N M I

low<------------------------------>high

does this fulfill our requirements? I is greater than M, M is greater than N. So, therefore, by looking at this, we can determine that N is less than I.