The temperature of an open

The temperature of an open room of volume $30 \mathrm{~m}^{3}$ increases from $17^{\circ} \mathrm{C}$ to $27^{\circ} \mathrm{C}$ due to sunshine. The atmospheric pressure in the room remains $1 \times 10^{5} \mathrm{~Pa}$. If $\mathrm{n}_{\mathrm{i}}$ and $\mathrm{n}_{\mathrm{f}}$ are the number of molecules in the room before and after heating, then $n_{f}-n_{i}$ will be :-