To the 4th problem was added a third value, grey.
The black and grey had to be locked together as one element and white as a separate element.
The 5th problem was arranging 5 rectangles in 3 values with value touching a rectangle of the same value. It was similar to the first problem of the 5 stones, one very large, one very small and the other three in between. Unfortunately the picture came out blurry (auto focus didn't work) but at least you can see what I did. I didn't realized the photo didn't come out until I had added the clothespin images...
This was actually my favorite problem of all I encountered. I also liked the expanded square a lot. I did learn a lot about negative space and design. Fascinating process.