These rectangles are similar, what is the scale factor?

Answer:
The scale factor is either 1/3 or 3/1 depending on how you see the shapes in relation to each other.
Step-by-step explanation:
XW~RQ
15/5 = 3/1
5/15 = 1/3
This can differ depending on whether you see it as a transformation or not. Hope this helps :)