Find the scale factor that was used

Scale factor is 2
30/15 = 2
20/10 = 2

The scale factor is 1.5.

15/10=1.5

30/20=1.5

Your answer would be A. 180.4= 180.40, as it is the same with an extra 0, and the zero really doesn't mean anything, unless as it's used when there's a number after it... for example, 180.404 as if you remove it, it would 180.44 which is completely different. Hope I helped!