12. Andrew calculates that $40 \%$ of $50 \%$ of $x$ is equal to $20 \%$ of $30 \%$ of $y$, where $x \neq 0$. Which of the following is true?
A $y=\frac{2 x}{3}$
B $y=\frac{4 x}{3}$
C $y=2 x$
D $y=\frac{8 x}{3}$
E $y=\frac{10 x}{3}$
12. E We are told that $40 \%$ of $50 \%$ of $x$ is equal to $20 \%$ of $30 \%$ of $y$.
Therefore $0.4 \times 0.5 \times x=0.2 \times 0.3 \times y$. Hence $0.2 \times x=0.2 \times 0.3 \times y$.
So $y=\frac{x}{0.3}=\frac{10 x}{3}$.