Answer:
4/5 or 0.8
Explanation:
this problem description is not very precise. it leaves out the definition what corners or sides of JKLM correspond to corners and sides of ABCD.
I assume J and K correlate to A and B, and JK is a long side of JKLM.
so, we are going from JKLM to ABCD.
that means we are going from larger to smaller (as JK = 15 and therefore larger than AB = 12).
what is the scale factor to go from 15 to 12 ?
15 × x = 12
x = 12/15 = 4/5 or 0.8