In the diagram, there is 1 shaded rectangle and 5 unshaded rectangles.
To find the ratio of shaded parts to unshaded parts, we can represent this as:
- Number of shaded rectangles = 1
- Number of unshaded rectangles = 5
Thus, the ratio of shaded parts to unshaded parts is expressed as:
1 (shaded) : 5 (unshaded)
Therefore, the correct answer is:
1 shaded to 5 unshaded.