$\mathrm{i}$ factor of glucose and urea are 1 : 1 respectively.

Moles of glucose $=\frac{{\mathrm{weight}}_{}}{\mathrm{Molecular\; wieght}}=\frac{1.8}{180}={10}^{-2}$

Moles of urea $=\frac{0.6}{60}={10}^{-2}$

Total mole of solute $={10}^{-2}+{10}^{-2}=2\times {10}^{-2}$

Concentration of solution $=\frac{2\times {10}^{-2}}{100\times {10}^{-3}}=0.2$

Osmotic pressure $\left(\mathrm{\pi }\right)=\mathrm{C}\mathrm{R}\mathrm{T}$

$=0.2\times 0.0821\times 300=4.926\mathrm{ }\mathrm{a}\mathrm{t}\mathrm{m}$