1/5
because 12/60 simplified is 1/5
When scaled down to a smaller shape and you need to find the scale factor, all you need to do is take corresponding sides and divide the smaller shape side by the larger shape side.
Sides that you could also use for the scale factor 12/60, 18/90, there is one more but the mouse is in the way I’ll assume that it’s 15/75, I could be wrong on that one though. I hope this helps.