Answer:
There are 34 boards in the stack
Explanation:
So, when solving this problem, you need to first build a diagram like the one on the attached picture. There you can see the graphical representation of the given problem.
So, we know that the 16th board from top to bottom is immediately above the
20'th board from up to down. This means that the board immediately below the 20'th board from up to down is the 14th board.
This gives us an answer of 14+20=34
Which is the answer. That is represented in the second diagram.