b
$Mass\, of\, the\,gas$ $=m$
At a fixed temperature and pressure, volume is fixed
Density of the gas $\rho=\frac{m}{V} \Rightarrow \frac{m}{V \cdot P}=\frac{m}{n R T}=x$
$x T=$ constant
At $10^{\circ} \mathrm{C}$ i.e., $283 \mathrm{K}, x T=x 283 \mathrm{K}$
At $110^{\circ} \mathrm{C}, x T=x^{\prime} 383 \mathrm{K}$
$\Rightarrow \quad x^{\prime}=\frac{283}{202} x$