Question

If $50\%$ of $(x-y)=30\%$ of $(x+y)$, what percent of $x$ is $y$?

• A. $25\%$
• B. $33\frac{1}{3}\%$
• C. $40\%$
• D. $400\%$

Answer 1

Answer: (A)

$25\%$

Given: $50\%$ of $(x-y)$ = $30\%$ of $(x+y)$

$\Rightarrow \frac{50}{100}\times (x-y)=\frac{30}{100}\times (x+y)$

$\Rightarrow 50x-50y=30x+30y$

$\Rightarrow 50x-30y=50y+30y$

$\Rightarrow 20x=80y$

$\Rightarrow \frac{1}{4}=y$

Hence y is $25\%$ of x.