# TEST QI puzzle - squares and circles on a 4x4 grid

This puzzle comes from an IQ test app called TEST QI. I cannot understand why the yellow option (the first option on the bottom row) is the right choice. Any idea?

Think this is it:

A sequence of infinitely long square/not square is moving across the board from top to bottom, left to right in backwards diagonals so you have the squares right.
A sequence of circle-no circle-circle (just those 3) is moving horizontally top to bottom left to right 1 space at a time. Often they are behind the squares. Its right side starts in box 3. As they move alternate between open and closed every other move. The open circle alternates on it's first move, the closed circle on it's 2nd move, then they alternate every other move after the initial alter. (i.e. an odd even pattern)

• I am not sure to have understood the pattern of the dots and circles. Jul 29, 2020 at 15:58
• For those looks like the dots as they move alternate between open and closed every other move. The circle alternates on it's first move, the dot on it's 2nd move, then they alternate every other move after the initial alter. (i.e. an odd even pattern)
– Amoz
Jul 29, 2020 at 16:03
• I agree mostly with your answer but I think the interpretation is that the circles change from hollow to full or vice versa when they are covered by the squares. It would be useful to include a diagram in your answer just to illustrate. Jul 29, 2020 at 16:32
• That is more intuitive. The squares are like little factories that manipulate the circles. It seemed like there was a relation but I wasn't quite seeing it.
– Amoz
Jul 29, 2020 at 16:42
• Following the tip of hexomino I finally understood. Nice catch! Thank you all. Jul 29, 2020 at 17:02