If 50% of (P – Q) = 30% of (P + Q) and Q = x% of P, then the value of x is :

$\frac{P-Q}{2}=(P+Q) \times \frac{30}{100}$

$\Rightarrow 5(\mathrm{P}-\mathrm{Q})=(\mathrm{P}+\mathrm{Q}) \times 3$

$\Rightarrow 5 \mathrm{P}-3 \mathrm{P}=5 \mathrm{Q}+3 \mathrm{Q}$

$\Rightarrow 2 \mathrm{P}=8 \mathrm{Q}$

$\Rightarrow \mathrm{P}=4 \mathrm{Q}=4 \times \frac{\mathrm{P} \times x}{100}$

$\Rightarrow \frac{4 x}{100}=1 \Rightarrow x=25$