Answer: 5
To get the similarity ratio, we must know that for the given triangles:

From the given, we know that:
UW = 2
WV = 2
VU = 1
IG = 10
GH = 10
HI = 5
Substitute these to the given equation and we will get:

With this, we have the similarity ratio of ΔGHI to ΔWVU is 5