Question

2 is to 1 as 0.3 is to ?

Answer 1

$2:1=0.3:x\\ \\ \Rightarrow \frac{2}{1}= \frac{0.3}{x}\\ \\ \Rightarrow \frac{x}{1}= \frac{0.3}{2}\\ \\ \Rightarrow x= \boxed{0.15}$

Answer 2

2:1=0.3:x
2*x=0.3*1
2x=0.3
x=0.3/2
  =0.15