The outside of this set of four cubic blocks with no space between blocks is painted. What is the number of painted square faces?

18

Step-by-step explanation:

There would be four faces on the top, left, bottom, and right.  That equals 16.  (4x4)

There would also 1 on each end, so you have to add 2.  That equal 18.

This is assuming you paint the faces on the bottom.  If you didn’t, the answer would be 14.  (But it doesn’t say not to paint them.)